21352639938 has 48 divisors (see below), whose sum is σ = 49746400704. Its totient is φ = 6092301600.

The previous prime is 21352639879. The next prime is 21352639939. The reversal of 21352639938 is 83993625312.

It is not an unprimeable number, because it can be changed into a prime (21352639939) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 163788 + ... + 263688.

It is an arithmetic number, because the mean of its divisors is an integer number (1036383348).

Almost surely, 2^21352639938 is an apocalyptic number.

21352639938 is an abundant number, since it is smaller than the sum of its proper divisors (28393760766).

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

21352639938 is a wasteful number, since it uses less digits than its factorization.

21352639938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100647 (or 100640 counting only the distinct ones).

The product of its digits is 2099520, while the sum is 51.

The spelling of 21352639938 in words is "twenty-one billion, three hundred fifty-two million, six hundred thirty-nine thousand, nine hundred thirty-eight".