21792180728840 has 64 divisors (see below), whose sum is σ = 49092289747200. Its totient is φ = 8706228715008.

The previous prime is 21792180728821. The next prime is 21792180728951. The reversal of 21792180728840 is 4882708129712.

It is a self number, because there is not a number n which added to its sum of digits gives 21792180728840.

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, 354388577 + ... + 354450063.

It is an arithmetic number, because the mean of its divisors is an integer number (767067027300).

Almost surely, 2^{21792180728840} is an apocalyptic number.

21792180728840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21792180728840 is an abundant number, since it is smaller than the sum of its proper divisors (27300109018360).

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

21792180728840 is a wasteful number, since it uses less digits than its factorization.

21792180728840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72174 (or 72170 counting only the distinct ones).

The product of its (nonzero) digits is 7225344, while the sum is 59.

The spelling of 21792180728840 in words is "twenty-one trillion, seven hundred ninety-two billion, one hundred eighty million, seven hundred twenty-eight thousand, eight hundred forty".