Every Day Counts
Centred Triangular Prime Days
 
Age: 20,358 days
Date of birth
Your 28th Centred Triangular Prime Day is on
Monday
when you will be
20,359 days old

A centred triangular prime is a centred triangular number that is prime.

Centred triangular numbers are of the form (3n2 + 3n + 2) / 2

A centred triangular number is a centred figurate number that represents a triangle with a dot in the centre and all other dots surrounding the centre in successive triangular layers.

The figures for the first four centred triangular numbers are shown below:

Remind me, please


Next Prime Events
Day Age
Event
Days Ahead
Year Age
16 Feb 2026
20,359
tomorrow
55
16 Feb 2026
20,359
tomorrow
55
02 Dec 2027
21,013
655
57
06 Dec 2028
21,383
1,025
58
20 Oct 2029
21,701
1,343
59
05 Nov 2031
22,447
2,089
61
05 Nov 2048
28,657
8,299
78
21 Oct 2052
30,103
9,745
82
26 Mar 2072
37,199
16,841
101
03 Mar 2078
39,367
19,009
107
02 Feb 2090
43,721
23,363
119
03 Jul 2103
48,619
28,261
133
27 Oct 2149
65,537
45,179
179
10 Dec 2244
100,279
79,921
274
29 Jun 2268
108,881
88,523
298
01 Apr 2329
131,071
110,713
358
24 Jul 7787
2,124,679
2,104,321
5817
Ordinal
Day Age
Date
Age
1st
19
10 Jun 1970
0
2nd
31
22 Jun 1970
0
3rd
109
08 Sep 1970
0
4th
199
07 Dec 1970
0
5th
409
05 Jul 1971
1
6th
571
14 Dec 1971
1
7th
631
12 Feb 1972
1
8th
829
28 Aug 1972
2
9th
1,489
19 Jun 1974
4
10th
1,999
11 Nov 1975
5
11th
2,341
18 Oct 1976
6
12th
2,971
10 Jul 1978
8
13th
3,529
19 Jan 1980
9
14th
4,621
15 Jan 1983
12
15th
4,789
02 Jul 1983
13
16th
7,039
29 Aug 1989
19
17th
7,669
21 May 1991
20
18th
8,779
04 Jun 1994
24
19th
9,721
01 Jan 1997
26
20th
10,459
09 Jan 1999
28
21st
10,711
18 Sep 1999
29
22nd
13,681
05 Nov 2007
37
23rd
14,851
18 Jan 2011
40
24th
16,069
20 May 2014
43
25th
16,381
28 Mar 2015
44
26th
17,659
26 Sep 2018
48
27th
20,011
05 Mar 2025
54
28th
20,359
16 Feb 2026
55
1
29th
23,251
17 Jan 2034
63
30th
25,939
28 May 2041
71
31st
27,541
16 Oct 2045
75
32nd
29,191
23 Apr 2050
79
33rd
29,611
17 Jun 2051
81
34th
31,321
21 Feb 2056
85
35th
34,429
25 Aug 2064
94
36th
36,739
22 Dec 2070
100
37th
40,099
04 Mar 2080
109
38th
40,591
09 Jul 2081
111
39th
42,589
28 Dec 2086
116