21678466664 has 16 divisors (see below), whose sum is σ = 40896496320. Its totient is φ = 10772734320.

The previous prime is 21678466627. The next prime is 21678466673. The reversal of 21678466664 is 46666487612.

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, 8310992 + ... + 8313599.

It is an arithmetic number, because the mean of its divisors is an integer number (2556031020).

Almost surely, 2^21678466664 is an apocalyptic number.

It is an amenable number.

21678466664 is a deficient number, since it is larger than the sum of its proper divisors (19218029656).

21678466664 is a wasteful number, since it uses less digits than its factorization.

21678466664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16624760 (or 16624756 counting only the distinct ones).

The product of its digits is 13934592, while the sum is 56.

The spelling of 21678466664 in words is "twenty-one billion, six hundred seventy-eight million, four hundred sixty-six thousand, six hundred sixty-four".