25661880 has 64 divisors (see below), whose sum is σ = 85543200. Its totient is φ = 6842880.

The previous prime is 25661869. The next prime is 25661929. The reversal of 25661880 is 8816652.

It is a happy number.

25661880 is a `hidden beast` number, since 2 + 566 + 18 + 80 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10801 + ... + 12960.

Almost surely, 2^25661880 is an apocalyptic number.

25661880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25661880 is an abundant number, since it is smaller than the sum of its proper divisors (59881320).

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

25661880 is a wasteful number, since it uses less digits than its factorization.

25661880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23781 (or 23771 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 25661880 is about 5065.7556198459. The cubic root of 25661880 is about 294.9597953444.

The spelling of 25661880 in words is "twenty-five million, six hundred sixty-one thousand, eight hundred eighty".