21399476736 has 320 divisors, whose sum is σ = 66184335360. Its totient is φ = 6079856640.

The previous prime is 21399476729. The next prime is 21399476773. The reversal of 21399476736 is 63767499312.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 20595705 + ... + 20596743.

It is an arithmetic number, because the mean of its divisors is an integer number (206826048).

Almost surely, 2^21399476736 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 21399476736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33092167680).

21399476736 is an abundant number, since it is smaller than the sum of its proper divisors (44784858624).

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

21399476736 is a wasteful number, since it uses less digits than its factorization.

21399476736 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1147 (or 1131 counting only the distinct ones).

The product of its digits is 10287648, while the sum is 57.

The spelling of 21399476736 in words is "twenty-one billion, three hundred ninety-nine million, four hundred seventy-six thousand, seven hundred thirty-six".