Every Day Counts
Centred Triangular Prime Days
 
Age: 23,233 days
Date of birth
Your 29th Centred Triangular Prime Day is on
Thursday
when you will be
23,251 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
27 Nov 2025
23,251
18
63
27 Nov 2025
23,251
18
63
05 Feb 2026
23,321
88
63
31 Jul 2026
23,497
264
64
27 Nov 2027
23,981
748
65
15 Sep 2040
28,657
5,424
78
31 Aug 2044
30,103
6,870
82
04 Feb 2064
37,199
13,966
101
11 Jan 2070
39,367
16,134
107
13 Dec 2081
43,721
20,488
119
28 Jan 2084
44,497
21,264
121
12 May 2095
48,619
25,386
133
06 Sep 2141
65,537
42,304
179
20 Oct 2236
100,279
77,046
274
09 May 2260
108,881
85,648
298
09 Feb 2321
131,071
107,838
358
03 Jun 7779
2,124,679
2,101,446
5817
Ordinal
Day Age
Date
Age
1st
19
20 Apr 1962
0
2nd
31
02 May 1962
0
3rd
109
19 Jul 1962
0
4th
199
17 Oct 1962
0
5th
409
15 May 1963
1
6th
571
24 Oct 1963
1
7th
631
23 Dec 1963
1
8th
829
08 Jul 1964
2
9th
1,489
29 Apr 1966
4
10th
1,999
21 Sep 1967
5
11th
2,341
28 Aug 1968
6
12th
2,971
20 May 1970
8
13th
3,529
29 Nov 1971
9
14th
4,621
25 Nov 1974
12
15th
4,789
12 May 1975
13
16th
7,039
09 Jul 1981
19
17th
7,669
31 Mar 1983
20
18th
8,779
14 Apr 1986
24
19th
9,721
11 Nov 1988
26
20th
10,459
19 Nov 1990
28
21st
10,711
29 Jul 1991
29
22nd
13,681
15 Sep 1999
37
23rd
14,851
28 Nov 2002
40
24th
16,069
30 Mar 2006
43
25th
16,381
05 Feb 2007
44
26th
17,659
06 Aug 2010
48
27th
20,011
13 Jan 2017
54
28th
20,359
27 Dec 2017
55
29th
23,251
27 Nov 2025
63
1
30th
25,939
07 Apr 2033
71
31st
27,541
26 Aug 2037
75
32nd
29,191
03 Mar 2042
79
33rd
29,611
27 Apr 2043
81
34th
31,321
01 Jan 2048
85
35th
34,429
05 Jul 2056
94
36th
36,739
01 Nov 2062
100
37th
40,099
13 Jan 2072
109
38th
40,591
19 May 2073
111
39th
42,589
07 Nov 2078
116