Every Day Counts
Centred Triangular Prime Days
 
Age: 20,003 days
Date of birth
Your 27th Centred Triangular Prime Day is on
Monday
when you will be
20,011 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
03 Nov 2025
20,011
8
54
03 Nov 2025
20,011
8
54
12 May 2026
20,201
198
55
15 Oct 2026
20,357
354
55
20 Jun 2030
21,701
1,698
59
05 Jul 2032
22,447
2,444
61
06 Jul 2049
28,657
8,654
78
21 Jun 2053
30,103
10,100
82
24 Nov 2072
37,199
17,196
101
01 Nov 2078
39,367
19,364
107
03 Oct 2090
43,721
23,718
119
02 Mar 2104
48,619
28,616
133
27 Jun 2150
65,537
45,534
179
10 Aug 2245
100,279
80,276
274
27 Feb 2269
108,881
88,878
298
30 Nov 2329
131,071
111,068
358
23 Mar 7788
2,124,679
2,104,676
5817
Ordinal
Day Age
Date
Age
1st
19
08 Feb 1971
0
2nd
31
20 Feb 1971
0
3rd
109
09 May 1971
0
4th
199
07 Aug 1971
0
5th
409
04 Mar 1972
1
6th
571
13 Aug 1972
1
7th
631
12 Oct 1972
1
8th
829
28 Apr 1973
2
9th
1,489
17 Feb 1975
4
10th
1,999
11 Jul 1976
5
11th
2,341
18 Jun 1977
6
12th
2,971
10 Mar 1979
8
13th
3,529
18 Sep 1980
9
14th
4,621
15 Sep 1983
12
15th
4,789
01 Mar 1984
13
16th
7,039
29 Apr 1990
19
17th
7,669
19 Jan 1992
20
18th
8,779
02 Feb 1995
24
19th
9,721
01 Sep 1997
26
20th
10,459
09 Sep 1999
28
21st
10,711
18 May 2000
29
22nd
13,681
05 Jul 2008
37
23rd
14,851
18 Sep 2011
40
24th
16,069
18 Jan 2015
43
25th
16,381
26 Nov 2015
44
26th
17,659
27 May 2019
48
27th
20,011
03 Nov 2025
54
1
28th
20,359
17 Oct 2026
55
29th
23,251
17 Sep 2034
63
30th
25,939
26 Jan 2042
71
31st
27,541
16 Jun 2046
75
32nd
29,191
22 Dec 2050
79
33rd
29,611
15 Feb 2052
81
34th
31,321
21 Oct 2056
85
35th
34,429
25 Apr 2065
94
36th
36,739
22 Aug 2071
100
37th
40,099
02 Nov 2080
109
38th
40,591
09 Mar 2082
111
39th
42,589
28 Aug 2087
116