21192393431664 has 480 divisors, whose sum is σ = 76235601234240. Its totient is φ = 5586931832832.

The previous prime is 21192393431621. The next prime is 21192393431773. The reversal of 21192393431664 is 46613439329112.

21192393431664 is a `hidden beast` number, since 2 + 1 + 1 + 9 + 239 + 34 + 316 + 64 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 21192393431664.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 741056214 + ... + 741084810.

It is an arithmetic number, because the mean of its divisors is an integer number (158824169238).

Almost surely, 2^{21192393431664} is an apocalyptic number.

21192393431664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21192393431664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38117800617120).

21192393431664 is an abundant number, since it is smaller than the sum of its proper divisors (55043207802576).

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

21192393431664 is a wasteful number, since it uses less digits than its factorization.

21192393431664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31334 (or 31315 counting only the distinct ones).

The product of its digits is 5038848, while the sum is 54.

The spelling of 21192393431664 in words is "twenty-one trillion, one hundred ninety-two billion, three hundred ninety-three million, four hundred thirty-one thousand, six hundred sixty-four".