21201057976 has 128 divisors (see below), whose sum is σ = 47777587200. Its totient is φ = 8629493760.

The previous prime is 21201057961. The next prime is 21201058001. The reversal of 21201057976 is 67975010212.

It is a congruent number.

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, 23069245 + ... + 23070163.

It is an arithmetic number, because the mean of its divisors is an integer number (373262400).

Almost surely, 2^21201057976 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 21201057976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23888793600).

21201057976 is an abundant number, since it is smaller than the sum of its proper divisors (26576529224).

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

21201057976 is a wasteful number, since it uses less digits than its factorization.

21201057976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1197 (or 1193 counting only the distinct ones).

The product of its (nonzero) digits is 52920, while the sum is 40.

The spelling of 21201057976 in words is "twenty-one billion, two hundred one million, fifty-seven thousand, nine hundred seventy-six".