Every Day Counts
Centred Triangular Prime Days
 
Age: 25,923 days
Date of birth
Your 30th Centred Triangular Prime Day is on
Monday
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
22 Nov 2026
25,931
8
70
30 Nov 2026
25,939
16
71
14 Sep 2027
26,227
304
71
04 Mar 2028
26,399
476
72
11 Dec 2028
26,681
758
73
10 May 2034
28,657
2,734
78
25 Apr 2038
30,103
4,180
82
28 Sep 2057
37,199
11,276
101
05 Sep 2063
39,367
13,444
107
07 Aug 2075
43,721
17,798
119
21 Sep 2077
44,497
18,574
121
03 Jan 2089
48,619
22,696
133
01 May 2135
65,537
39,614
179
14 Jun 2230
100,279
74,356
274
01 Jan 2254
108,881
82,958
298
04 Oct 2314
131,071
105,148
358
25 Jan 7773
2,124,679
2,098,756
5817
Ordinal
Day Age
Date
Age
1st
19
13 Dec 1955
0
2nd
31
25 Dec 1955
0
3rd
109
12 Mar 1956
0
4th
199
10 Jun 1956
0
5th
409
06 Jan 1957
1
6th
571
17 Jun 1957
1
7th
631
16 Aug 1957
1
8th
829
02 Mar 1958
2
9th
1,489
22 Dec 1959
4
10th
1,999
15 May 1961
5
11th
2,341
22 Apr 1962
6
12th
2,971
12 Jan 1964
8
13th
3,529
23 Jul 1965
9
14th
4,621
19 Jul 1968
12
15th
4,789
03 Jan 1969
13
16th
7,039
03 Mar 1975
19
17th
7,669
22 Nov 1976
20
18th
8,779
07 Dec 1979
24
19th
9,721
06 Jul 1982
26
20th
10,459
13 Jul 1984
28
21st
10,711
22 Mar 1985
29
22nd
13,681
09 May 1993
37
23rd
14,851
22 Jul 1996
40
24th
16,069
22 Nov 1999
43
25th
16,381
29 Sep 2000
44
26th
17,659
30 Mar 2004
48
27th
20,011
07 Sep 2010
54
28th
20,359
21 Aug 2011
55
29th
23,251
22 Jul 2019
63
30th
25,939
30 Nov 2026
71
1
31st
27,541
20 Apr 2031
75
32nd
29,191
26 Oct 2035
79
33rd
29,611
19 Dec 2036
81
34th
31,321
25 Aug 2041
85
35th
34,429
27 Feb 2050
94
36th
36,739
25 Jun 2056
100
37th
40,099
06 Sep 2065
109
38th
40,591
11 Jan 2067
111
39th
42,589
01 Jul 2072
116