21157594776 has 192 divisors, whose sum is σ = 59540832000. Its totient is φ = 6784081920.

The previous prime is 21157594769. The next prime is 21157594781. The reversal of 21157594776 is 67749575112.

21157594776 is a `hidden beast` number, since 2 + 115 + 7 + 59 + 477 + 6 = 666.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 44170105 + ... + 44170583.

It is an arithmetic number, because the mean of its divisors is an integer number (310108500).

Almost surely, 2^21157594776 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 21157594776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29770416000).

21157594776 is an abundant number, since it is smaller than the sum of its proper divisors (38383237224).

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

21157594776 is a wasteful number, since it uses less digits than its factorization.

21157594776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 754 (or 747 counting only the distinct ones).

The product of its digits is 3704400, while the sum is 54.

The spelling of 21157594776 in words is "twenty-one billion, one hundred fifty-seven million, five hundred ninety-four thousand, seven hundred seventy-six".