15555625 has 10 divisors (see below), whose sum is σ = 19439090. Its totient is φ = 12444000.

The previous prime is 15555587. The next prime is 15555647. The reversal of 15555625 is 52655551.

It can be written as a sum of positive squares in 5 ways, for example, as 11539609 + 4016016 = 3397^2 + 2004^2 .

It is not a de Polignac number, because 15555625 - 2¹⁷ = 15424553 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 11820 + ... + 13069.

It is an arithmetic number, because the mean of its divisors is an integer number (1943909).

Almost surely, 2^15555625 is an apocalyptic number.

It is an amenable number.

15555625 is a deficient number, since it is larger than the sum of its proper divisors (3883465).

15555625 is an frugal number, since it uses more digits than its factorization.

15555625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24909 (or 24894 counting only the distinct ones).

The product of its digits is 37500, while the sum is 34.

The square root of 15555625 is about 3944.0619924134. The cubic root of 15555625 is about 249.6294510452.

The spelling of 15555625 in words is "fifteen million, five hundred fifty-five thousand, six hundred twenty-five".