Every Day Counts
Centred Triangular Prime Days
 
Age: 16,367 days
Date of birth
Your 25th Centred Triangular Prime Day is on
Wednesday
when you will be
16,381 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 Feb 2026
16,369
2
44
11 Mar 2026
16,381
14
44
11 Mar 2026
16,381
14
44
11 Mar 2026
16,381
14
44
07 Sep 2026
16,561
194
45
06 Dec 2026
16,651
284
45
16 Jun 2027
16,843
476
46
31 Mar 2029
17,497
1,130
47
13 Feb 2031
18,181
1,814
49
07 Jun 2034
19,391
3,024
53
05 Dec 2035
19,937
3,570
54
20 Oct 2059
28,657
12,290
78
17 Jan 2101
43,721
27,354
119
16 Jun 2114
48,619
32,252
133
10 Oct 2160
65,537
49,170
179
24 Nov 2255
100,279
83,912
274
15 Mar 2340
131,071
114,704
358
Ordinal
Day Age
Date
Age
1st
19
24 May 1981
0
2nd
31
05 Jun 1981
0
3rd
109
22 Aug 1981
0
4th
199
20 Nov 1981
0
5th
409
18 Jun 1982
1
6th
571
27 Nov 1982
1
7th
631
26 Jan 1983
1
8th
829
12 Aug 1983
2
9th
1,489
02 Jun 1985
4
10th
1,999
25 Oct 1986
5
11th
2,341
02 Oct 1987
6
12th
2,971
23 Jun 1989
8
13th
3,529
02 Jan 1991
9
14th
4,621
29 Dec 1993
12
15th
4,789
15 Jun 1994
13
16th
7,039
12 Aug 2000
19
17th
7,669
04 May 2002
20
18th
8,779
18 May 2005
24
19th
9,721
16 Dec 2007
26
20th
10,459
23 Dec 2009
28
21st
10,711
01 Sep 2010
29
22nd
13,681
19 Oct 2018
37
23rd
14,851
01 Jan 2022
40
24th
16,069
03 May 2025
43
25th
16,381
11 Mar 2026
44
1
26th
17,659
09 Sep 2029
48
27th
20,011
17 Feb 2036
54
28th
20,359
30 Jan 2037
55
29th
23,251
31 Dec 2044
63
30th
25,939
11 May 2052
71
31st
27,541
29 Sep 2056
75
32nd
29,191
06 Apr 2061
79
33rd
29,611
31 May 2062
81
34th
31,321
04 Feb 2067
85
35th
34,429
09 Aug 2075
94
36th
36,739
05 Dec 2081
100
37th
40,099
16 Feb 2091
109
38th
40,591
22 Jun 2092
111
39th
42,589
11 Dec 2097
116