21236307165 has 32 divisors (see below), whose sum is σ = 38041660800. Its totient is φ = 11239562880.

The previous prime is 21236307133. The next prime is 21236307179. The reversal of 21236307165 is 56170363212.

21236307165 is a `hidden beast` number, since 2 + 1 + 2 + 3 + 630 + 7 + 16 + 5 = 666.

It is not a de Polignac number, because 21236307165 - 2⁵ = 21236307133 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 582720 + ... + 618089.

It is an arithmetic number, because the mean of its divisors is an integer number (1188801900).

Almost surely, 2^21236307165 is an apocalyptic number.

It is an amenable number.

21236307165 is a deficient number, since it is larger than the sum of its proper divisors (16805353635).

21236307165 is a wasteful number, since it uses less digits than its factorization.

21236307165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1200954 (or 1200948 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 36.

The spelling of 21236307165 in words is "twenty-one billion, two hundred thirty-six million, three hundred seven thousand, one hundred sixty-five".