639982660 has 48 divisors (see below), whose sum is σ = 1368412416. Its totient is φ = 251361792.

The previous prime is 639982639. The next prime is 639982661. The reversal of 639982660 is 66289936.

It is not an unprimeable number, because it can be changed into a prime (639982661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 579669 + ... + 580771.

It is an arithmetic number, because the mean of its divisors is an integer number (28508592).

Almost surely, 2^639982660 is an apocalyptic number.

It is an amenable number.

639982660 is an abundant number, since it is smaller than the sum of its proper divisors (728429756).

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

639982660 is a wasteful number, since it uses less digits than its factorization.

639982660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1612 (or 1610 counting only the distinct ones).

The product of its (nonzero) digits is 839808, while the sum is 49.

The square root of 639982660 is about 25297.8785671842. The cubic root of 639982660 is about 861.7660930471.

The spelling of 639982660 in words is "six hundred thirty-nine million, nine hundred eighty-two thousand, six hundred sixty".