640518504976 has 135 divisors (see below), whose sum is σ = 1463222694573. Its totient is φ = 270829641600.

The previous prime is 640518504949. The next prime is 640518504979. The reversal of 640518504976 is 679405815046.

The square root of 640518504976 is 800324.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 615402594576 + 25115910400 = 784476^2 + 158480^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640518504979) 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 26 ways as a sum of consecutive naturals, for example, 2263316131 + ... + 2263316413.

Almost surely, 2^640518504976 is an apocalyptic number.

640518504976 is the 800324-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640518504976

640518504976 is an abundant number, since it is smaller than the sum of its proper divisors (822704189597).

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

640518504976 is an equidigital number, since it uses as much as digits as its factorization.

640518504976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 790 (or 393 counting only the distinct ones).

The product of its (nonzero) digits is 7257600, while the sum is 55.

The spelling of 640518504976 in words is "six hundred forty billion, five hundred eighteen million, five hundred four thousand, nine hundred seventy-six".