25399864 has 16 divisors (see below), whose sum is σ = 54428400. Its totient is φ = 10885632.

The previous prime is 25399849. The next prime is 25399867. The reversal of 25399864 is 46899352.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25399867) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 226729 + ... + 226840.

It is an arithmetic number, because the mean of its divisors is an integer number (3401775).

Almost surely, 2^25399864 is an apocalyptic number.

It is an amenable number.

25399864 is an abundant number, since it is smaller than the sum of its proper divisors (29028536).

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

25399864 is a wasteful number, since it uses less digits than its factorization.

25399864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 453582 (or 453578 counting only the distinct ones).

The product of its digits is 466560, while the sum is 46.

The square root of 25399864 is about 5039.8277748352. The cubic root of 25399864 is about 293.9524812521.

It can be divided in two parts, 2539 and 9864, that added together give a triangular number (12403 = T₁₅₇).

The spelling of 25399864 in words is "twenty-five million, three hundred ninety-nine thousand, eight hundred sixty-four".