Every Day Counts
Centred Triangular Prime Days
 
Age: 17,598 days
Date of birth
Your 26th Centred Triangular Prime Day is on
Wednesday
when you will be
17,659 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
06 Sep 2025
17,599
tomorrow
48
05 Nov 2025
17,659
61
48
13 Sep 2026
17,971
373
49
11 Apr 2027
18,181
583
49
21 Aug 2027
18,313
715
50
19 Dec 2027
18,433
835
50
21 Jul 2029
19,013
1,415
52
03 Aug 2030
19,391
1,793
53
22 Sep 2030
19,441
1,843
53
31 Jan 2032
19,937
2,339
54
16 Dec 2055
28,657
11,059
78
14 Mar 2097
43,721
26,123
119
12 Aug 2110
48,619
31,021
133
06 Dec 2156
65,537
47,939
179
20 Jan 2252
100,279
82,681
274
11 May 2336
131,071
113,473
358
02 Sep 7794
2,124,679
2,107,081
5817
Ordinal
Day Age
Date
Age
1st
19
20 Jul 1977
0
2nd
31
01 Aug 1977
0
3rd
109
18 Oct 1977
0
4th
199
16 Jan 1978
0
5th
409
14 Aug 1978
1
6th
571
23 Jan 1979
1
7th
631
24 Mar 1979
1
8th
829
08 Oct 1979
2
9th
1,489
29 Jul 1981
4
10th
1,999
21 Dec 1982
5
11th
2,341
28 Nov 1983
6
12th
2,971
19 Aug 1985
8
13th
3,529
28 Feb 1987
9
14th
4,621
24 Feb 1990
12
15th
4,789
11 Aug 1990
13
16th
7,039
08 Oct 1996
19
17th
7,669
30 Jun 1998
20
18th
8,779
14 Jul 2001
24
19th
9,721
11 Feb 2004
26
20th
10,459
18 Feb 2006
28
21st
10,711
28 Oct 2006
29
22nd
13,681
15 Dec 2014
37
23rd
14,851
27 Feb 2018
40
24th
16,069
29 Jun 2021
43
25th
16,381
07 May 2022
44
26th
17,659
05 Nov 2025
48
1
27th
20,011
14 Apr 2032
54
28th
20,359
28 Mar 2033
55
29th
23,251
26 Feb 2041
63
30th
25,939
07 Jul 2048
71
31st
27,541
25 Nov 2052
75
32nd
29,191
02 Jun 2057
79
33rd
29,611
27 Jul 2058
81
34th
31,321
02 Apr 2063
85
35th
34,429
05 Oct 2071
94
36th
36,739
31 Jan 2078
100
37th
40,099
14 Apr 2087
109
38th
40,591
18 Aug 2088
111
39th
42,589
06 Feb 2094
116