15651665525 has 12 divisors (see below), whose sum is σ = 19430222532. Its totient is φ = 12507037440.

The previous prime is 15651665467. The next prime is 15651665539. The reversal of 15651665525 is 52556615651.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 317053636 + 15334611889 = 17806^2 + 123833^2 .

It is not a de Polignac number, because 15651665525 - 2⁸ = 15651665269 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 15651665525.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 335012 + ... + 378861.

It is an arithmetic number, because the mean of its divisors is an integer number (1619185211).

Almost surely, 2^15651665525 is an apocalyptic number.

It is an amenable number.

15651665525 is a deficient number, since it is larger than the sum of its proper divisors (3778557007).

15651665525 is an equidigital number, since it uses as much as digits as its factorization.

15651665525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 714760 (or 714755 counting only the distinct ones).

The product of its digits is 1350000, while the sum is 47.

The spelling of 15651665525 in words is "fifteen billion, six hundred fifty-one million, six hundred sixty-five thousand, five hundred twenty-five".