25809664 has 36 divisors (see below), whose sum is σ = 52796520. Its totient is φ = 12584960.

The previous prime is 25809629. The next prime is 25809671. The reversal of 25809664 is 46690852.

It is a happy number.

It is a super-2 number, since 2×25809664² = 1332277511585792, which contains 22 as substring.

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, 9267 + ... + 11725.

It is an arithmetic number, because the mean of its divisors is an integer number (1466570).

Almost surely, 2^25809664 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 25809664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26398260).

25809664 is an abundant number, since it is smaller than the sum of its proper divisors (26986856).

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

25809664 is an equidigital number, since it uses as much as digits as its factorization.

25809664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2516 (or 2502 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 40.

The square root of 25809664 is about 5080.3212496849. The cubic root of 25809664 is about 295.5249257731.

The spelling of 25809664 in words is "twenty-five million, eight hundred nine thousand, six hundred sixty-four".