15625640 has 32 divisors (see below), whose sum is σ = 35479080. Its totient is φ = 6193152.

The previous prime is 15625639. The next prime is 15625661. The reversal of 15625640 is 4652651.

It can be written as a sum of positive squares in 4 ways, for example, as 2937796 + 12687844 = 1714^2 + 3562^2 .

It is a sliding number, since 15625640 = 640 + 15625000 and 1/640 + 1/15625000 = 0.0015625640.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2792 + ... + 6248.

Almost surely, 2^15625640 is an apocalyptic number.

15625640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15625640 is an abundant number, since it is smaller than the sum of its proper divisors (19853440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

15625640 is a wasteful number, since it uses less digits than its factorization.

15625640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3581 (or 3577 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 15625640 is about 3952.9280286896. The cubic root of 15625640 is about 250.0034132867.

It can be divided in two parts, 15625 and 640, that multiplied together give a 7-th power (10000000 = 10⁷).

The spelling of 15625640 in words is "fifteen million, six hundred twenty-five thousand, six hundred forty".