21057937768 has 48 divisors (see below), whose sum is σ = 46014376320. Its totient is φ = 9008239968.

The previous prime is 21057937721. The next prime is 21057937801. The reversal of 21057937768 is 86773975012.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 165321 + ... + 263527.

It is an arithmetic number, because the mean of its divisors is an integer number (958632840).

Almost surely, 2^21057937768 is an apocalyptic number.

21057937768 is a gapful number since it is divisible by the number (28) 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 21057937768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23007188160).

21057937768 is an abundant number, since it is smaller than the sum of its proper divisors (24956438552).

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

21057937768 is a wasteful number, since it uses less digits than its factorization.

21057937768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98774 (or 98763 counting only the distinct ones).

The product of its (nonzero) digits is 4445280, while the sum is 55.

The spelling of 21057937768 in words is "twenty-one billion, fifty-seven million, nine hundred thirty-seven thousand, seven hundred sixty-eight".