21330790656 has 144 divisors (see below), whose sum is σ = 65072784000. Its totient is φ = 6076514304.

The previous prime is 21330790639. The next prime is 21330790661. The reversal of 21330790656 is 65609703312.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1870540 + ... + 1881908.

Almost surely, 2^21330790656 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 21330790656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32536392000).

21330790656 is an abundant number, since it is smaller than the sum of its proper divisors (43741993344).

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

21330790656 is a wasteful number, since it uses less digits than its factorization.

21330790656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11744 (or 11730 counting only the distinct ones).

The product of its (nonzero) digits is 204120, while the sum is 42.

The spelling of 21330790656 in words is "twenty-one billion, three hundred thirty million, seven hundred ninety thousand, six hundred fifty-six".