25521816 has 16 divisors (see below), whose sum is σ = 63804600. Its totient is φ = 8507264.

The previous prime is 25521809. The next prime is 25521817. The reversal of 25521816 is 61812552.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25521817) 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, 531681 + ... + 531728.

Almost surely, 2^25521816 is an apocalyptic number.

It is an amenable number.

25521816 is an abundant number, since it is smaller than the sum of its proper divisors (38282784).

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

25521816 is a wasteful number, since it uses less digits than its factorization.

25521816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1063418 (or 1063414 counting only the distinct ones).

The product of its digits is 4800, while the sum is 30.

The square root of 25521816 is about 5051.9121132498. The cubic root of 25521816 is about 294.4221802661.

The spelling of 25521816 in words is "twenty-five million, five hundred twenty-one thousand, eight hundred sixteen".