640854374 has 4 divisors (see below), whose sum is σ = 961281564. Its totient is φ = 320427186.

The previous prime is 640854337. The next prime is 640854407. The reversal of 640854374 is 473458046.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160213592 + ... + 160213595.

It is an arithmetic number, because the mean of its divisors is an integer number (240320391).

Almost surely, 2^640854374 is an apocalyptic number.

640854374 is a deficient number, since it is larger than the sum of its proper divisors (320427190).

640854374 is a wasteful number, since it uses less digits than its factorization.

640854374 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320427189.

The product of its (nonzero) digits is 322560, while the sum is 41.

The square root of 640854374 is about 25315.1016983934. The cubic root of 640854374 is about 862.1571832018.

The spelling of 640854374 in words is "six hundred forty million, eight hundred fifty-four thousand, three hundred seventy-four".