21717216868 has 24 divisors (see below), whose sum is σ = 38897736192. Its totient is φ = 10604577984.

The previous prime is 21717216793. The next prime is 21717216887. The reversal of 21717216868 is 86861271712.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37705 + ... + 211792.

It is an arithmetic number, because the mean of its divisors is an integer number (1620739008).

Almost surely, 2^21717216868 is an apocalyptic number.

It is an amenable number.

21717216868 is a deficient number, since it is larger than the sum of its proper divisors (17180519324).

21717216868 is a wasteful number, since it uses less digits than its factorization.

21717216868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250011 (or 250009 counting only the distinct ones).

The product of its digits is 451584, while the sum is 49.

The spelling of 21717216868 in words is "twenty-one billion, seven hundred seventeen million, two hundred sixteen thousand, eight hundred sixty-eight".