21377658865 has 16 divisors (see below), whose sum is σ = 27489466368. Its totient is φ = 15902185216.

The previous prime is 21377658823. The next prime is 21377658871. The reversal of 21377658865 is 56885677312.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21377658865 - 2⁷ = 21377658737 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1508017 + ... + 1522126.

It is an arithmetic number, because the mean of its divisors is an integer number (1718091648).

Almost surely, 2^21377658865 is an apocalyptic number.

It is an amenable number.

21377658865 is a deficient number, since it is larger than the sum of its proper divisors (6111807503).

21377658865 is a wasteful number, since it uses less digits than its factorization.

21377658865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3030248.

The product of its digits is 16934400, while the sum is 58.

The spelling of 21377658865 in words is "twenty-one billion, three hundred seventy-seven million, six hundred fifty-eight thousand, eight hundred sixty-five".