21868388372 has 12 divisors (see below), whose sum is σ = 38793922356. Its totient is φ = 10784410560.

The previous prime is 21868388363. The next prime is 21868388383. The reversal of 21868388372 is 27388386812.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 19163972356 + 2704416016 = 138434^2 + 52004^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37445579 + ... + 37446162.

It is an arithmetic number, because the mean of its divisors is an integer number (3232826863).

Almost surely, 2^21868388372 is an apocalyptic number.

It is an amenable number.

21868388372 is a deficient number, since it is larger than the sum of its proper divisors (16925533984).

21868388372 is a wasteful number, since it uses less digits than its factorization.

21868388372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74891818 (or 74891816 counting only the distinct ones).

The product of its digits is 6193152, while the sum is 56.

The spelling of 21868388372 in words is "twenty-one billion, eight hundred sixty-eight million, three hundred eighty-eight thousand, three hundred seventy-two".