25657664 has 28 divisors (see below), whose sum is σ = 51451764. Its totient is φ = 12693504.

The previous prime is 25657633. The next prime is 25657691. The reversal of 25657664 is 46675652.

It can be written as a sum of positive squares in 2 ways, for example, as 15366400 + 10291264 = 3920^2 + 3208^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4142 + ... + 8274.

It is an arithmetic number, because the mean of its divisors is an integer number (1837563).

Almost surely, 2^25657664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25657664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25725882).

25657664 is an abundant number, since it is smaller than the sum of its proper divisors (25794100).

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

25657664 is an equidigital number, since it uses as much as digits as its factorization.

25657664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4242 (or 4232 counting only the distinct ones).

The product of its digits is 302400, while the sum is 41.

The square root of 25657664 is about 5065.3394752968. The cubic root of 25657664 is about 294.9436414408.

The spelling of 25657664 in words is "twenty-five million, six hundred fifty-seven thousand, six hundred sixty-four".