21664264263 has 8 divisors (see below), whose sum is σ = 28887374208. Its totient is φ = 14441998584.

The previous prime is 21664264261. The next prime is 21664264267. The reversal of 21664264263 is 36246246612.

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

It is not a de Polignac number, because 21664264263 - 2¹ = 21664264261 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21664264261) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 148545 + ... + 255722.

It is an arithmetic number, because the mean of its divisors is an integer number (3610921776).

Almost surely, 2^21664264263 is an apocalyptic number.

21664264263 is a deficient number, since it is larger than the sum of its proper divisors (7223109945).

21664264263 is a wasteful number, since it uses less digits than its factorization.

21664264263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 422133.

The product of its digits is 497664, while the sum is 42.

The spelling of 21664264263 in words is "twenty-one billion, six hundred sixty-four million, two hundred sixty-four thousand, two hundred sixty-three".