21065161506 has 32 divisors (see below), whose sum is σ = 42695251200. Its totient is φ = 6927697920.

The previous prime is 21065161483. The next prime is 21065161519. The reversal of 21065161506 is 60516156012.

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, 652096 + ... + 683636.

It is an arithmetic number, because the mean of its divisors is an integer number (1334226600).

Almost surely, 2^21065161506 is an apocalyptic number.

21065161506 is an abundant number, since it is smaller than the sum of its proper divisors (21630089694).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21065161506 is a wasteful number, since it uses less digits than its factorization.

21065161506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33034.

The product of its (nonzero) digits is 10800, while the sum is 33.

The spelling of 21065161506 in words is "twenty-one billion, sixty-five million, one hundred sixty-one thousand, five hundred six".