21372043968 has 224 divisors, whose sum is σ = 69043296000. Its totient is φ = 6428989440.

The previous prime is 21372043921. The next prime is 21372043991. The reversal of 21372043968 is 86934027312.

21372043968 is a `hidden beast` number, since 2 + 137 + 20 + 439 + 68 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

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, 2638068 + ... + 2646156.

It is an arithmetic number, because the mean of its divisors is an integer number (308229000).

Almost surely, 2^21372043968 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 21372043968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34521648000).

21372043968 is an abundant number, since it is smaller than the sum of its proper divisors (47671252032).

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

21372043968 is a wasteful number, since it uses less digits than its factorization.

21372043968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8260 (or 8244 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 45.

The spelling of 21372043968 in words is "twenty-one billion, three hundred seventy-two million, forty-three thousand, nine hundred sixty-eight".