639825665164 has 96 divisors (see below), whose sum is σ = 1323633024000. Its totient is φ = 270482446080.

The previous prime is 639825665153. The next prime is 639825665207. The reversal of 639825665164 is 461566528936.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 32702817 + ... + 32722375.

It is an arithmetic number, because the mean of its divisors is an integer number (13787844000).

Almost surely, 2^639825665164 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639825665164, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (661816512000).

639825665164 is an abundant number, since it is smaller than the sum of its proper divisors (683807358836).

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

639825665164 is a wasteful number, since it uses less digits than its factorization.

639825665164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19908 (or 19892 counting only the distinct ones).

The product of its digits is 55987200, while the sum is 61.

The spelling of 639825665164 in words is "six hundred thirty-nine billion, eight hundred twenty-five million, six hundred sixty-five thousand, one hundred sixty-four".