15685561253 has 2 divisors, whose sum is σ = 15685561254. Its totient is φ = 15685561252.

The previous prime is 15685561247. The next prime is 15685561261. The reversal of 15685561253 is 35216558651.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8929872004 + 6755689249 = 94498^2 + 82193^2 .

It is a cyclic number.

It is not a de Polignac number, because 15685561253 - 2⁴ = 15685561237 is a prime.

It is a super-2 number, since 2×15685561253² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 15685561198 and 15685561207.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15685561223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7842780626 + 7842780627.

It is an arithmetic number, because the mean of its divisors is an integer number (7842780627).

Almost surely, 2^15685561253 is an apocalyptic number.

It is an amenable number.

15685561253 is a deficient number, since it is larger than the sum of its proper divisors (1).

15685561253 is an equidigital number, since it uses as much as digits as its factorization.

15685561253 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1080000, while the sum is 47.

The spelling of 15685561253 in words is "fifteen billion, six hundred eighty-five million, five hundred sixty-one thousand, two hundred fifty-three".