25640877506 has 16 divisors (see below), whose sum is σ = 38539330200. Its totient is φ = 12794462208.

The previous prime is 25640877499. The next prime is 25640877523. The reversal of 25640877506 is 60577804652.

It can be written as a sum of positive squares in 4 ways, for example, as 12334101481 + 13306776025 = 111059^2 + 115355^2 .

It is a Curzon 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, 2136290 + ... + 2148258.

Almost surely, 2^25640877506 is an apocalyptic number.

25640877506 is a deficient number, since it is larger than the sum of its proper divisors (12898452694).

25640877506 is a wasteful number, since it uses less digits than its factorization.

25640877506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14053.

The product of its (nonzero) digits is 2822400, while the sum is 50.

The spelling of 25640877506 in words is "twenty-five billion, six hundred forty million, eight hundred seventy-seven thousand, five hundred six".