640979480 has 32 divisors (see below), whose sum is σ = 1462523040. Its totient is φ = 252779520.

The previous prime is 640979477. The next prime is 640979501. The reversal of 640979480 is 84979046.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 110009 + ... + 115688.

It is an arithmetic number, because the mean of its divisors is an integer number (45703845).

Almost surely, 2^640979480 is an apocalyptic number.

It is an amenable number.

640979480 is an abundant number, since it is smaller than the sum of its proper divisors (821543560).

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

640979480 is a wasteful number, since it uses less digits than its factorization.

640979480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 225779 (or 225775 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 47.

The square root of 640979480 is about 25317.5725534657. The cubic root of 640979480 is about 862.2132822798.

The spelling of 640979480 in words is "six hundred forty million, nine hundred seventy-nine thousand, four hundred eighty".