Every Day Counts
Centred Triangular Prime Days
 
Age: 25,925 days
Date of birth
Your 30th Centred Triangular Prime Day is on
Wednesday
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
17 Mar 2026
25,931
6
70
25 Mar 2026
25,939
14
71
07 Jan 2027
26,227
302
71
28 Jun 2027
26,399
474
72
05 Apr 2028
26,681
756
73
02 Sep 2033
28,657
2,732
78
18 Aug 2037
30,103
4,178
82
21 Jan 2057
37,199
11,274
101
29 Dec 2062
39,367
13,442
107
30 Nov 2074
43,721
17,796
119
14 Jan 2077
44,497
18,572
121
28 Apr 2088
48,619
22,694
133
24 Aug 2134
65,537
39,612
179
07 Oct 2229
100,279
74,354
274
26 Apr 2253
108,881
82,956
298
27 Jan 2314
131,071
105,146
358
20 May 7772
2,124,679
2,098,754
5817
Ordinal
Day Age
Date
Age
1st
19
07 Apr 1955
0
2nd
31
19 Apr 1955
0
3rd
109
06 Jul 1955
0
4th
199
04 Oct 1955
0
5th
409
01 May 1956
1
6th
571
10 Oct 1956
1
7th
631
09 Dec 1956
1
8th
829
25 Jun 1957
2
9th
1,489
16 Apr 1959
4
10th
1,999
07 Sep 1960
5
11th
2,341
15 Aug 1961
6
12th
2,971
07 May 1963
8
13th
3,529
15 Nov 1964
9
14th
4,621
12 Nov 1967
12
15th
4,789
28 Apr 1968
13
16th
7,039
26 Jun 1974
19
17th
7,669
17 Mar 1976
20
18th
8,779
01 Apr 1979
24
19th
9,721
29 Oct 1981
26
20th
10,459
06 Nov 1983
28
21st
10,711
15 Jul 1984
29
22nd
13,681
01 Sep 1992
37
23rd
14,851
15 Nov 1995
40
24th
16,069
17 Mar 1999
43
25th
16,381
23 Jan 2000
44
26th
17,659
24 Jul 2003
48
27th
20,011
31 Dec 2009
54
28th
20,359
14 Dec 2010
55
29th
23,251
14 Nov 2018
63
30th
25,939
25 Mar 2026
71
1
31st
27,541
13 Aug 2030
75
32nd
29,191
18 Feb 2035
79
33rd
29,611
13 Apr 2036
81
34th
31,321
18 Dec 2040
85
35th
34,429
22 Jun 2049
94
36th
36,739
19 Oct 2055
100
37th
40,099
30 Dec 2064
109
38th
40,591
06 May 2066
111
39th
42,589
25 Oct 2071
116