21596919816 has 64 divisors (see below), whose sum is σ = 57297844800. Its totient is φ = 6760153088.

The previous prime is 21596919803. The next prime is 21596919821. The reversal of 21596919816 is 61891969512.

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 15 ways as a sum of consecutive naturals, for example, 121000 + ... + 240488.

It is an arithmetic number, because the mean of its divisors is an integer number (895278825).

Almost surely, 2^21596919816 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 21596919816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28648922400).

21596919816 is an abundant number, since it is smaller than the sum of its proper divisors (35700924984).

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

21596919816 is a wasteful number, since it uses less digits than its factorization.

21596919816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119958 (or 119954 counting only the distinct ones).

The product of its digits is 2099520, while the sum is 57.

The spelling of 21596919816 in words is "twenty-one billion, five hundred ninety-six million, nine hundred nineteen thousand, eight hundred sixteen".