25215440920 has 32 divisors (see below), whose sum is σ = 58564897920. Its totient is φ = 9760815360.

The previous prime is 25215440917. The next prime is 25215440941. The reversal of 25215440920 is 2904451252.

It is a happy number.

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10166277 + ... + 10168756.

It is an arithmetic number, because the mean of its divisors is an integer number (1830153060).

Almost surely, 2^25215440920 is an apocalyptic number.

25215440920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25215440920 is an abundant number, since it is smaller than the sum of its proper divisors (33349457000).

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

25215440920 is a wasteful number, since it uses less digits than its factorization.

25215440920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20335075 (or 20335071 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 34.

The spelling of 25215440920 in words is "twenty-five billion, two hundred fifteen million, four hundred forty thousand, nine hundred twenty".