Every Day Counts
Centred Triangular Prime Days
 
Age: 25,932 days
Date of birth
Your 30th Centred Triangular Prime Day is on
Saturday
when you will be
25,939 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 Dec 2025
25,933
tomorrow
71
03 Jan 2026
25,939
7
71
18 Oct 2026
26,227
295
71
08 Apr 2027
26,399
467
72
15 Jan 2028
26,681
749
73
13 Jun 2033
28,657
2,725
78
29 May 2037
30,103
4,171
82
01 Nov 2056
37,199
11,267
101
09 Oct 2062
39,367
13,435
107
10 Sep 2074
43,721
17,789
119
25 Oct 2076
44,497
18,565
121
07 Feb 2088
48,619
22,687
133
04 Jun 2134
65,537
39,605
179
18 Jul 2229
100,279
74,347
274
04 Feb 2253
108,881
82,949
298
07 Nov 2313
131,071
105,139
358
29 Feb 7772
2,124,679
2,098,747
5817
Ordinal
Day Age
Date
Age
1st
19
16 Jan 1955
0
2nd
31
28 Jan 1955
0
3rd
109
16 Apr 1955
0
4th
199
15 Jul 1955
0
5th
409
10 Feb 1956
1
6th
571
21 Jul 1956
1
7th
631
19 Sep 1956
1
8th
829
05 Apr 1957
2
9th
1,489
25 Jan 1959
4
10th
1,999
18 Jun 1960
5
11th
2,341
26 May 1961
6
12th
2,971
15 Feb 1963
8
13th
3,529
26 Aug 1964
9
14th
4,621
23 Aug 1967
12
15th
4,789
07 Feb 1968
13
16th
7,039
06 Apr 1974
19
17th
7,669
27 Dec 1975
20
18th
8,779
10 Jan 1979
24
19th
9,721
09 Aug 1981
26
20th
10,459
17 Aug 1983
28
21st
10,711
25 Apr 1984
29
22nd
13,681
12 Jun 1992
37
23rd
14,851
26 Aug 1995
40
24th
16,069
26 Dec 1998
43
25th
16,381
03 Nov 1999
44
26th
17,659
04 May 2003
48
27th
20,011
11 Oct 2009
54
28th
20,359
24 Sep 2010
55
29th
23,251
25 Aug 2018
63
30th
25,939
03 Jan 2026
71
1
31st
27,541
24 May 2030
75
32nd
29,191
29 Nov 2034
79
33rd
29,611
23 Jan 2036
81
34th
31,321
28 Sep 2040
85
35th
34,429
02 Apr 2049
94
36th
36,739
30 Jul 2055
100
37th
40,099
10 Oct 2064
109
38th
40,591
14 Feb 2066
111
39th
42,589
05 Aug 2071
116