21663265315 has 16 divisors (see below), whose sum is σ = 26512984800. Its totient is φ = 16986557952.

The previous prime is 21663265259. The next prime is 21663265339. The reversal of 21663265315 is 51356236612.

It is a cyclic number.

It is not a de Polignac number, because 21663265315 - 2¹⁷ = 21663134243 is a prime.

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, 226876 + ... + 307894.

It is an arithmetic number, because the mean of its divisors is an integer number (1657061550).

Almost surely, 2^21663265315 is an apocalyptic number.

21663265315 is a deficient number, since it is larger than the sum of its proper divisors (4849719485).

21663265315 is a wasteful number, since it uses less digits than its factorization.

21663265315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82086.

The product of its digits is 194400, while the sum is 40.

The spelling of 21663265315 in words is "twenty-one billion, six hundred sixty-three million, two hundred sixty-five thousand, three hundred fifteen".