21940938072 has 128 divisors (see below), whose sum is σ = 65136441600. Its totient is φ = 6818978304.

The previous prime is 21940938037. The next prime is 21940938073. The reversal of 21940938072 is 27083904912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21940938073) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 364983 + ... + 420825.

It is an arithmetic number, because the mean of its divisors is an integer number (508878450).

Almost surely, 2^21940938072 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 21940938072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32568220800).

21940938072 is an abundant number, since it is smaller than the sum of its proper divisors (43195503528).

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

21940938072 is a wasteful number, since it uses less digits than its factorization.

21940938072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55982 (or 55972 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The spelling of 21940938072 in words is "twenty-one billion, nine hundred forty million, nine hundred thirty-eight thousand, seventy-two".