25640724 has 24 divisors (see below), whose sum is σ = 60380320. Its totient is φ = 8468064.

The previous prime is 25640683. The next prime is 25640729. The reversal of 25640724 is 42704652.

It is a junction number, because it is equal to n+sod(n) for n = 25640691 and 25640700.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25640729) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 8494 + ... + 11109.

Almost surely, 2^25640724 is an apocalyptic number.

It is an amenable number.

25640724 is an abundant number, since it is smaller than the sum of its proper divisors (34739596).

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

25640724 is a wasteful number, since it uses less digits than its factorization.

25640724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19719 (or 19717 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 30.

The square root of 25640724 is about 5063.6670506659. The cubic root of 25640724 is about 294.8787167817.

The spelling of 25640724 in words is "twenty-five million, six hundred forty thousand, seven hundred twenty-four".