25640864 has 12 divisors (see below), whose sum is σ = 50480514. Its totient is φ = 12820416.

The previous prime is 25640863. The next prime is 25640893. The reversal of 25640864 is 46804652.

It can be written as a sum of positive squares in only one way, i.e., 15272464 + 10368400 = 3908^2 + 3220^2 .

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (25640863) 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 as a sum of consecutive naturals, namely, 400607 + ... + 400670.

Almost surely, 2^25640864 is an apocalyptic number.

It is an amenable number.

25640864 is a deficient number, since it is larger than the sum of its proper divisors (24839650).

25640864 is an equidigital number, since it uses as much as digits as its factorization.

25640864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 801287 (or 801279 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 35.

The square root of 25640864 is about 5063.6808746208. The cubic root of 25640864 is about 294.8792534663.

The spelling of 25640864 in words is "twenty-five million, six hundred forty thousand, eight hundred sixty-four".