25696640 has 32 divisors (see below), whose sum is σ = 61432560. Its totient is φ = 10278400.

The previous prime is 25696637. The next prime is 25696663. The reversal of 25696640 is 4669652.

It is a tau number, because it is divible by the number of its divisors (32).

It is a junction number, because it is equal to n+sod(n) for n = 25696594 and 25696603.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19436 + ... + 20715.

Almost surely, 2^25696640 is an apocalyptic number.

25696640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25696640 is an abundant number, since it is smaller than the sum of its proper divisors (35735920).

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

25696640 is an equidigital number, since it uses as much as digits as its factorization.

25696640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40170 (or 40158 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 38.

The square root of 25696640 is about 5069.1853388883. The cubic root of 25696640 is about 295.0929133739.

The spelling of 25696640 in words is "twenty-five million, six hundred ninety-six thousand, six hundred forty".