21233637665 has 8 divisors (see below), whose sum is σ = 25482032448. Its totient is φ = 16985798640.

The previous prime is 21233637613. The next prime is 21233637679. The reversal of 21233637665 is 56673633212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21233637665 - 2²⁰ = 21232589089 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49667 + ... + 211976.

It is an arithmetic number, because the mean of its divisors is an integer number (3185254056).

Almost surely, 2^21233637665 is an apocalyptic number.

It is an amenable number.

21233637665 is a deficient number, since it is larger than the sum of its proper divisors (4248394783).

21233637665 is a wasteful number, since it uses less digits than its factorization.

21233637665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277879.

The product of its digits is 816480, while the sum is 44.

The spelling of 21233637665 in words is "twenty-one billion, two hundred thirty-three million, six hundred thirty-seven thousand, six hundred sixty-five".