25138877638 has 32 divisors (see below), whose sum is σ = 44064959040. Its totient is φ = 10532820480.

The previous prime is 25138877627. The next prime is 25138877657. The reversal of 25138877638 is 83677883152.

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, 148218 + ... + 268786.

It is an arithmetic number, because the mean of its divisors is an integer number (1377029970).

Almost surely, 2^25138877638 is an apocalyptic number.

25138877638 is a deficient number, since it is larger than the sum of its proper divisors (18926081402).

25138877638 is a wasteful number, since it uses less digits than its factorization.

25138877638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120912.

The product of its digits is 13547520, while the sum is 58.

The spelling of 25138877638 in words is "twenty-five billion, one hundred thirty-eight million, eight hundred seventy-seven thousand, six hundred thirty-eight".