25402220640 has 72 divisors (see below), whose sum is σ = 86685082848. Its totient is φ = 6773925120.

The previous prime is 25402220629. The next prime is 25402220681. The reversal of 25402220640 is 4602220452.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8818776 + ... + 8821655.

It is an arithmetic number, because the mean of its divisors is an integer number (1203959484).

Almost surely, 2^25402220640 is an apocalyptic number.

25402220640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25402220640 is an abundant number, since it is smaller than the sum of its proper divisors (61282862208).

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

25402220640 is a wasteful number, since it uses less digits than its factorization.

25402220640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17640452 (or 17640441 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 27.

The spelling of 25402220640 in words is "twenty-five billion, four hundred two million, two hundred twenty thousand, six hundred forty".