25664638 has 8 divisors (see below), whose sum is σ = 38601288. Its totient is φ = 12797544.

The previous prime is 25664629. The next prime is 25664657. The reversal of 25664638 is 83646652.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 25664638.

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, 16456 + ... + 17947.

It is an arithmetic number, because the mean of its divisors is an integer number (4825161).

Almost surely, 2^25664638 is an apocalyptic number.

25664638 is a deficient number, since it is larger than the sum of its proper divisors (12936650).

25664638 is a wasteful number, since it uses less digits than its factorization.

25664638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34778.

The product of its digits is 207360, while the sum is 40.

The square root of 25664638 is about 5066.0278325331. The cubic root of 25664638 is about 294.9703618601.

The spelling of 25664638 in words is "twenty-five million, six hundred sixty-four thousand, six hundred thirty-eight".