51math.com - dns.ninja

`51math.com`

DNSSEC	⚠️ Not signed
A	47.89.250.56^{🇺🇸 Alibaba-Cloud47.89.224.0/19 Alibaba Cloud}
NS	`dns19.hichina.com` ⭐
		A	2408:4009:501::27^{🇨🇳 Alibaba-Cloud2408:4009:501::/48}
		A	39.96.153.40^{🇨🇳 Alibaba-Cloud39.96.0.0/14 CT BeiJing IDC}
		A	39.96.153.60^{🇨🇳 Alibaba-Cloud39.96.0.0/14 CT BeiJing IDC}
		A	47.118.199.200^{🇨🇳 Alibaba-Cloud47.118.128.0/17 Alibaba (US) Technology Co., Ltd.}
		A	47.118.199.220^{🇨🇳 Alibaba-Cloud47.118.128.0/17 Alibaba (US) Technology Co., Ltd.}
		A	120.76.107.40^{🇨🇳 Alibaba-Cloud120.76.0.0/17}
		A	120.76.107.60^{🇨🇳 Alibaba-Cloud120.76.0.0/17}
		A	139.224.142.100^{🇨🇳 Alibaba-Cloud139.224.128.0/17 China Internet Network Information Center Floor1, Building No.1 C/-Chinese Academy of Sciences 4, South 4th Street Haidian District,}
		A	139.224.142.110^{🇨🇳 Alibaba-Cloud139.224.128.0/17 China Internet Network Information Center Floor1, Building No.1 C/-Chinese Academy of Sciences 4, South 4th Street Haidian District,}
NS	`dns20.hichina.com`
		A	2408:4009:501::28^{🇨🇳 Alibaba-Cloud2408:4009:501::/48}
		A	39.96.153.38^{🇨🇳 Alibaba-Cloud39.96.0.0/14 CT BeiJing IDC}
		A	39.96.153.61^{🇨🇳 Alibaba-Cloud39.96.0.0/14 CT BeiJing IDC}
		A	47.118.199.198^{🇨🇳 Alibaba-Cloud47.118.128.0/17 Alibaba (US) Technology Co., Ltd.}
		A	47.118.199.222^{🇨🇳 Alibaba-Cloud47.118.128.0/17 Alibaba (US) Technology Co., Ltd.}
		A	120.76.107.38^{🇨🇳 Alibaba-Cloud120.76.0.0/17}
		A	120.76.107.61^{🇨🇳 Alibaba-Cloud120.76.0.0/17}
		A	139.224.142.98^{🇨🇳 Alibaba-Cloud139.224.128.0/17 China Internet Network Information Center Floor1, Building No.1 C/-Chinese Academy of Sciences 4, South 4th Street Haidian District,}
		A	139.224.142.108^{🇨🇳 Alibaba-Cloud139.224.128.0/17 China Internet Network Information Center Floor1, Building No.1 C/-Chinese Academy of Sciences 4, South 4th Street Haidian District,}
MX	`mail.51math.com` ⭐
		A	62.151.176.131^{🇪🇸 IONOS-AS62.151.176.0/21 arsys.es NGCS}
			PTR	`mail.rootmaths.com`
TXT	`201709300000003zxdhw7k8z53vmxjdo58ec5umuewd0s39tjpewkfkzakri58cc`
TXT	`v=spf1 a mx ptr mx:mail.51math.com ~all`
SOA	`dns19.hichina.com`hostmaster@hichina.com 2026-06-04 #13

`com`

	DNSSEC	🔒 Signed (DS record present)
	NS	`a.gtld-servers.net` ⭐
	NS	`b.gtld-servers.net`
	NS	`c.gtld-servers.net`
	NS	`d.gtld-servers.net`
	NS	`e.gtld-servers.net`
	NS	`f.gtld-servers.net`
	NS	`g.gtld-servers.net`
	NS	`h.gtld-servers.net`
	NS	`i.gtld-servers.net`
	NS	`j.gtld-servers.net`
	NS	`k.gtld-servers.net`
	NS	`l.gtld-servers.net`
	NS	`m.gtld-servers.net`
	SOA	`a.gtld-servers.net`nstld@verisign-grs.com serial=1786167294

Subdomains

mail.51math.com

Same first word

51math.cn

51math.com

Similar names

math51.com

DNS History

5 records (4 active, 1 former)

●NSdns19.hichina.com2015-05-27 → 2026-08-08 · 2 obs

● 2015-05-27 04:37:08
● 2026-08-08 06:03:06

●NSdns20.hichina.com2015-05-27 → 2026-08-08 · 2 obs

● 2015-05-27 04:37:08
● 2026-08-08 06:03:06

●MXmail.51math.com2015-05-27 → 2026-08-08 · 2 obs

● 2015-05-27 04:37:08
● 2026-08-08 06:03:06

○A208.109.4.2012015-05-27 → 2017-06-19 · 4 obs

● 2015-05-27 04:37:08
● 2017-06-19 10:11:34
○ 2026-02-20 19:31:24
○ 2026-08-08 06:03:06

●A47.89.250.562026-02-20 → 2026-08-08 · 3 obs

○ 2017-06-19 10:11:34
● 2026-02-20 19:31:24
● 2026-08-08 06:03:06

🔍 DNS Trace

📋 Delegation Chain

Zone	Nameservers	Glue
com	a.gtld-servers.net, m.gtld-servers.net, l.gtld-servers.net, g.gtld-servers.net...	-
51math.com	dns19.hichina.com, dns20.hichina.com	18 records

✅ Authoritative Response

Server:120.76.107.40

NS records: dns19.hichina.com, dns20.hichina.com

🔒 DNSSEC Status

⚠️ Insecure (no DNSSEC)

No DS record for 51math.com (unsigned zone)

⏱️ Timing

Total: 513ms | Queries: -

📄 Records

Type	Count	Sample Data
A	1	`47.89.250.56`
NS	2	`dns20.hichina.com, dns19.hichina.com`
MX	1	`mail.51math.com (pri: 1)`
TXT	2	`v=spf1 a mx ptr mx:mail.51math.com ~all, 201709300000003zxdhw7k8z53vmxjdo58ec5umu`
SOA	1	`dns19.hichina.com hostmaster.hichina.com`

📌 Glue Records Collected

Total: 18

Out-of-bailiwick: 18 (dns19.hichina.com, dns19.hichina.com, dns19.hichina.com...)

Analysis

Hierarchy

The domain mail.51math.com falls under the parent 51math.com.

IP Addresses

51math.com directs to one IP number, which is 47.89.250.56.

Other host names, such as rootmaths.com, share IP numbers with 51math.com.

Name Servers

51math.com is delegated to two name servers: dns19.hichina.com and dns20.hichina.com.

51math.com has the same name server delegation as a number of other domains, such as hncyp.com, y611.cn, bianhun.com and two more.

At least some of 51math.com's name servers are shared with other domains, for example startrackxj.com, hega.cn, hzmg.gov.cn and two more.

These name servers tend to be deployed in combination with the name servers expirens3.hichina.com and expirens4.hichina.com.

Host names resolving to 9 IP numbers:

dns19.hichina.com resolves to 39.96.153.40, 39.96.153.60, 47.118.199.200 and 6 other IP addresses.

dns20.hichina.com resolves to 39.96.153.38, 39.96.153.61, 47.118.199.198 and 6 other IP addresses.

Mail Servers

51math.com routes its mail through a single mail server, mail.51math.com.

51math.com and domains like mail.51math.com share an identical mail server configuration.

mail.51math.com resolves to a single IP number: 62.151.176.131.