15720625 has 10 divisors (see below), whose sum is σ = 19645274. Its totient is φ = 12576000.

The previous prime is 15720587. The next prime is 15720641. The reversal of 15720625 is 52602751.

It can be written as a sum of positive squares in 5 ways, for example, as 5779216 + 9941409 = 2404^2 + 3153^2 .

It is not a de Polignac number, because 15720625 - 2¹⁵ = 15687857 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 15720593 and 15720602.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 11952 + ... + 13201.

Almost surely, 2^15720625 is an apocalyptic number.

It is an amenable number.

15720625 is a deficient number, since it is larger than the sum of its proper divisors (3924649).

15720625 is an frugal number, since it uses more digits than its factorization.

15720625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25173 (or 25158 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 15720625 is about 3964.9243372352. The cubic root of 15720625 is about 250.5089631230.

The spelling of 15720625 in words is "fifteen million, seven hundred twenty thousand, six hundred twenty-five".