1639320864 has 48 divisors (see below), whose sum is σ = 4310923680. Its totient is φ = 545461760.

The previous prime is 1639320821. The next prime is 1639320871. The reversal of 1639320864 is 4680239361.

It is a tau number, because it is divible by the number of its divisors (48).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39619 + ... + 69629.

It is an arithmetic number, because the mean of its divisors is an integer number (89810910).

Almost surely, 2^1639320864 is an apocalyptic number.

It is an amenable number.

1639320864 is an abundant number, since it is smaller than the sum of its proper divisors (2671602816).

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

1639320864 is a wasteful number, since it uses less digits than its factorization.

1639320864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30593 (or 30585 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 42.

The square root of 1639320864 is about 40488.5275602855. The cubic root of 1639320864 is about 1179.1109035621.

The spelling of 1639320864 in words is "one billion, six hundred thirty-nine million, three hundred twenty thousand, eight hundred sixty-four".