21801216576 has 28 divisors (see below), whose sum is σ = 57682386032. Its totient is φ = 7267072128.

The previous prime is 21801216527. The next prime is 21801216601. The reversal of 21801216576 is 67561210812.

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 3 ways as a sum of consecutive naturals, for example, 56773810 + ... + 56774193.

Almost surely, 2^21801216576 is an apocalyptic number.

It is an amenable number.

21801216576 is an abundant number, since it is smaller than the sum of its proper divisors (35881169456).

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

21801216576 is a wasteful number, since it uses less digits than its factorization.

21801216576 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113548018 (or 113548008 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 39.

The spelling of 21801216576 in words is "twenty-one billion, eight hundred one million, two hundred sixteen thousand, five hundred seventy-six".