15664625 has 16 divisors (see below), whose sum is σ = 19740240. Its totient is φ = 12409600.

The previous prime is 15664609. The next prime is 15664637. The reversal of 15664625 is 52646651.

It can be written as a sum of positive squares in 8 ways, for example, as 14205361 + 1459264 = 3769^2 + 1208^2 .

It is not a de Polignac number, because 15664625 - 2⁴ = 15664609 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13571 + ... + 14679.

It is an arithmetic number, because the mean of its divisors is an integer number (1233765).

Almost surely, 2^15664625 is an apocalyptic number.

It is an amenable number.

15664625 is a deficient number, since it is larger than the sum of its proper divisors (4075615).

15664625 is a wasteful number, since it uses less digits than its factorization.

15664625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1237 (or 1227 counting only the distinct ones).

The product of its digits is 43200, while the sum is 35.

The square root of 15664625 is about 3957.8561115836. The cubic root of 15664625 is about 250.2111549375.

The spelling of 15664625 in words is "fifteen million, six hundred sixty-four thousand, six hundred twenty-five".