21616843456 has 28 divisors (see below), whose sum is σ = 46195611952. Its totient is φ = 9977004288.

The previous prime is 21616843447. The next prime is 21616843477. The reversal of 21616843456 is 65434861612.

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, 12990060 + ... + 12991723.

It is an arithmetic number, because the mean of its divisors is an integer number (1649843284).

Almost surely, 2^21616843456 is an apocalyptic number.

21616843456 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21616843456 is an abundant number, since it is smaller than the sum of its proper divisors (24578768496).

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

21616843456 is a wasteful number, since it uses less digits than its factorization.

21616843456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25981808 (or 25981798 counting only the distinct ones).

The product of its digits is 829440, while the sum is 46.

The spelling of 21616843456 in words is "twenty-one billion, six hundred sixteen million, eight hundred forty-three thousand, four hundred fifty-six".