38640072534 has 64 divisors (see below), whose sum is σ = 90608094720. Its totient is φ = 10755360000.

The previous prime is 38640072529. The next prime is 38640072547. The reversal of 38640072534 is 43527004683.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 675034 + ... + 730034.

It is an arithmetic number, because the mean of its divisors is an integer number (1415751480).

Almost surely, 2^38640072534 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 38640072534, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45304047360).

38640072534 is an abundant number, since it is smaller than the sum of its proper divisors (51968022186).

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

38640072534 is a wasteful number, since it uses less digits than its factorization.

38640072534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55445.

The product of its (nonzero) digits is 483840, while the sum is 42.

The spelling of 38640072534 in words is "thirty-eight billion, six hundred forty million, seventy-two thousand, five hundred thirty-four".