640509974 has 16 divisors (see below), whose sum is σ = 1036439712. Its totient is φ = 295114368.

The previous prime is 640509973. The next prime is 640509977. The reversal of 640509974 is 479905046.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640509973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5354 + ... + 36189.

It is an arithmetic number, because the mean of its divisors is an integer number (64777482).

Almost surely, 2^640509974 is an apocalyptic number.

640509974 is a deficient number, since it is larger than the sum of its proper divisors (395929738).

640509974 is a wasteful number, since it uses less digits than its factorization.

640509974 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42151.

The product of its (nonzero) digits is 272160, while the sum is 44.

The square root of 640509974 is about 25308.2985204458. The cubic root of 640509974 is about 862.0027122579.

The spelling of 640509974 in words is "six hundred forty million, five hundred nine thousand, nine hundred seventy-four".