Every Day Counts
Centred Triangular Prime Days
 
Age: 23,238 days
Date of birth
Your 29th Centred Triangular Prime Day is on
Tuesday
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
28 Oct 2025
23,251
13
63
28 Oct 2025
23,251
13
63
06 Jan 2026
23,321
83
63
01 Jul 2026
23,497
259
64
28 Oct 2027
23,981
743
65
16 Aug 2040
28,657
5,419
78
01 Aug 2044
30,103
6,865
82
05 Jan 2064
37,199
13,961
101
12 Dec 2069
39,367
16,129
107
13 Nov 2081
43,721
20,483
119
29 Dec 2083
44,497
21,259
121
12 Apr 2095
48,619
25,381
133
07 Aug 2141
65,537
42,299
179
20 Sep 2236
100,279
77,041
274
09 Apr 2260
108,881
85,643
298
10 Jan 2321
131,071
107,833
358
04 May 7779
2,124,679
2,101,441
5817
Ordinal
Day Age
Date
Age
1st
19
21 Mar 1962
0
2nd
31
02 Apr 1962
0
3rd
109
19 Jun 1962
0
4th
199
17 Sep 1962
0
5th
409
15 Apr 1963
1
6th
571
24 Sep 1963
1
7th
631
23 Nov 1963
1
8th
829
08 Jun 1964
2
9th
1,489
30 Mar 1966
4
10th
1,999
22 Aug 1967
5
11th
2,341
29 Jul 1968
6
12th
2,971
20 Apr 1970
8
13th
3,529
30 Oct 1971
9
14th
4,621
26 Oct 1974
12
15th
4,789
12 Apr 1975
13
16th
7,039
09 Jun 1981
19
17th
7,669
01 Mar 1983
20
18th
8,779
15 Mar 1986
24
19th
9,721
12 Oct 1988
26
20th
10,459
20 Oct 1990
28
21st
10,711
29 Jun 1991
29
22nd
13,681
16 Aug 1999
37
23rd
14,851
29 Oct 2002
40
24th
16,069
28 Feb 2006
43
25th
16,381
06 Jan 2007
44
26th
17,659
07 Jul 2010
48
27th
20,011
14 Dec 2016
54
28th
20,359
27 Nov 2017
55
29th
23,251
28 Oct 2025
63
1
30th
25,939
08 Mar 2033
71
31st
27,541
27 Jul 2037
75
32nd
29,191
01 Feb 2042
79
33rd
29,611
28 Mar 2043
81
34th
31,321
02 Dec 2047
85
35th
34,429
05 Jun 2056
94
36th
36,739
02 Oct 2062
100
37th
40,099
14 Dec 2071
109
38th
40,591
19 Apr 2073
111
39th
42,589
08 Oct 2078
116