Every Day Counts
Centred Triangular Prime Days
 
Age: 31,304 days
Date of birth
Your 34th Centred Triangular Prime Day is on
Monday
when you will be
31,321 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
14 Jul 2025
31,307
3
85
28 Jul 2025
31,321
17
85
05 Feb 2026
31,513
209
86
04 May 2026
31,601
297
86
29 Mar 2031
33,391
2,087
91
07 Jun 2031
33,461
2,157
91
31 Aug 2041
37,199
5,895
101
08 Aug 2047
39,367
8,063
107
10 Jul 2059
43,721
12,417
119
24 Aug 2061
44,497
13,193
121
06 Dec 2072
48,619
17,315
133
03 Apr 2119
65,537
34,233
179
17 May 2214
100,279
68,975
274
04 Dec 2237
108,881
77,577
298
05 Sep 2298
131,071
99,767
358
28 Dec 7756
2,124,679
2,093,375
5817
Ordinal
Day Age
Date
Age
1st
19
15 Nov 1939
0
2nd
31
27 Nov 1939
0
3rd
109
13 Feb 1940
0
4th
199
13 May 1940
0
5th
409
09 Dec 1940
1
6th
571
20 May 1941
1
7th
631
19 Jul 1941
1
8th
829
02 Feb 1942
2
9th
1,489
24 Nov 1943
4
10th
1,999
17 Apr 1945
5
11th
2,341
25 Mar 1946
6
12th
2,971
15 Dec 1947
8
13th
3,529
25 Jun 1949
9
14th
4,621
21 Jun 1952
12
15th
4,789
06 Dec 1952
13
16th
7,039
03 Feb 1959
19
17th
7,669
25 Oct 1960
20
18th
8,779
09 Nov 1963
24
19th
9,721
08 Jun 1966
26
20th
10,459
15 Jun 1968
28
21st
10,711
22 Feb 1969
29
22nd
13,681
11 Apr 1977
37
23rd
14,851
24 Jun 1980
40
24th
16,069
25 Oct 1983
43
25th
16,381
01 Sep 1984
44
26th
17,659
02 Mar 1988
48
27th
20,011
10 Aug 1994
54
28th
20,359
24 Jul 1995
55
29th
23,251
24 Jun 2003
63
30th
25,939
02 Nov 2010
71
31st
27,541
23 Mar 2015
75
32nd
29,191
28 Sep 2019
79
33rd
29,611
21 Nov 2020
81
34th
31,321
28 Jul 2025
85
1
35th
34,429
30 Jan 2034
94
36th
36,739
28 May 2040
100
37th
40,099
09 Aug 2049
109
38th
40,591
14 Dec 2050
111
39th
42,589
03 Jun 2056
116