640786874 has 32 divisors (see below), whose sum is σ = 1184808576. Its totient is φ = 253108800.

The previous prime is 640786847. The next prime is 640786889. The reversal of 640786874 is 478687046.

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, 135449 + ... + 140099.

It is an arithmetic number, because the mean of its divisors is an integer number (37025268).

Almost surely, 2^640786874 is an apocalyptic number.

640786874 is a deficient number, since it is larger than the sum of its proper divisors (544021702).

640786874 is a wasteful number, since it uses less digits than its factorization.

640786874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5430.

The product of its (nonzero) digits is 1806336, while the sum is 50.

The square root of 640786874 is about 25313.7684669825. The cubic root of 640786874 is about 862.1269123345.

The spelling of 640786874 in words is "six hundred forty million, seven hundred eighty-six thousand, eight hundred seventy-four".