38721521664 has 576 divisors, whose sum is σ = 138032294400. Its totient is φ = 10683187200.

The previous prime is 38721521647. The next prime is 38721521669. The reversal of 38721521664 is 46612512783.

It is a tau number, because it is divible by the number of its divisors (576).

Its product of digits (483840) is a multiple of the sum of its prime divisors (504).

It is not an unprimeable number, because it can be changed into a prime (38721521669) 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 47 ways as a sum of consecutive naturals, for example, 83994394 + ... + 83994854.

It is an arithmetic number, because the mean of its divisors is an integer number (239639400).

Almost surely, 2^38721521664 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 38721521664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (69016147200).

38721521664 is an abundant number, since it is smaller than the sum of its proper divisors (99310772736).

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

38721521664 is a wasteful number, since it uses less digits than its factorization.

38721521664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 537 (or 504 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The spelling of 38721521664 in words is "thirty-eight billion, seven hundred twenty-one million, five hundred twenty-one thousand, six hundred sixty-four".