21191938272 has 72 divisors (see below), whose sum is σ = 62208619200. Its totient is φ = 6836106240.

The previous prime is 21191938259. The next prime is 21191938279. The reversal of 21191938272 is 27283919112.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21191938279) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1177897 + ... + 1195752.

It is an arithmetic number, because the mean of its divisors is an integer number (864008600).

Almost surely, 2^21191938272 is an apocalyptic number.

It is an amenable number.

21191938272 is an abundant number, since it is smaller than the sum of its proper divisors (41016680928).

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

21191938272 is a wasteful number, since it uses less digits than its factorization.

21191938272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2373696 (or 2373685 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The spelling of 21191938272 in words is "twenty-one billion, one hundred ninety-one million, nine hundred thirty-eight thousand, two hundred seventy-two".