25600640 has 128 divisors (see below), whose sum is σ = 70171920. Its totient is φ = 8847360.

The previous prime is 25600639. The next prime is 25600651. The reversal of 25600640 is 4600652.

It can be written as a sum of positive squares in 8 ways, for example, as 2637376 + 22963264 = 1624^2 + 4792^2 .

It is a tau number, because it is divible by the number of its divisors (128).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 141350 + ... + 141530.

Almost surely, 2^25600640 is an apocalyptic number.

25600640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25600640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35085960).

25600640 is an abundant number, since it is smaller than the sum of its proper divisors (44571280).

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

25600640 is a wasteful number, since it uses less digits than its factorization.

25600640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230 (or 218 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 25600640 is about 5059.7075014273. The cubic root of 25600640 is about 294.7249758918.

The spelling of 25600640 in words is "twenty-five million, six hundred thousand, six hundred forty".