21069974720 has 28 divisors (see below), whose sum is σ = 50172878064. Its totient is φ = 8427989760.

The previous prime is 21069974713. The next prime is 21069974747. The reversal of 21069974720 is 2747996012.

It is a hoax number, since the sum of its digits (47) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32921516 + ... + 32922155.

Almost surely, 2^21069974720 is an apocalyptic number.

21069974720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21069974720 is an abundant number, since it is smaller than the sum of its proper divisors (29102903344).

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

21069974720 is an equidigital number, since it uses as much as digits as its factorization.

21069974720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65843688 (or 65843678 counting only the distinct ones).

The product of its (nonzero) digits is 381024, while the sum is 47.

The spelling of 21069974720 in words is "twenty-one billion, sixty-nine million, nine hundred seventy-four thousand, seven hundred twenty".