64631318388 has 96 divisors (see below), whose sum is σ = 189924489216. Its totient is φ = 16649200512.

The previous prime is 64631318377. The next prime is 64631318407. The reversal of 64631318388 is 88381313646.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 64631318388.

It is a congruent number.

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, 641256 + ... + 735167.

It is an arithmetic number, because the mean of its divisors is an integer number (1978380096).

Almost surely, 2^64631318388 is an apocalyptic number.

It is an amenable number.

64631318388 is an abundant number, since it is smaller than the sum of its proper divisors (125293170828).

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

64631318388 is a wasteful number, since it uses less digits than its factorization.

64631318388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1376493 (or 1376491 counting only the distinct ones).

The product of its digits is 1990656, while the sum is 51.

The spelling of 64631318388 in words is "sixty-four billion, six hundred thirty-one million, three hundred eighteen thousand, three hundred eighty-eight".