22165552161 has 9 divisors (see below), whose sum is σ = 32017553841. Its totient is φ = 14776737012.

The previous prime is 22165552147. The next prime is 22165552231. The reversal of 22165552161 is 16125556122.

The square root of 22165552161 is 148881.

It is a perfect power (a square), and thus also a powerful number.

22165552161 is a `hidden beast` number, since 2 + 21 + 6 + 55 + 521 + 61 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 22165552161 - 2⁷ = 22165552033 is a prime.

It is not an unprimeable number, because it can be changed into a prime (22165550161) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 421830 + ... + 471456.

Almost surely, 2^22165552161 is an apocalyptic number.

22165552161 is the 148881-st square number.

22165552161 is the 74441-st centered octagonal number.

It is an amenable number.

22165552161 is a deficient number, since it is larger than the sum of its proper divisors (9852001680).

22165552161 is an frugal number, since it uses more digits than its factorization.

22165552161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99260 (or 49630 counting only the distinct ones).

The product of its digits is 36000, while the sum is 36.

Multiplying 22165552161 by its sum of digits (36), we get a square (797959877796 = 893286²).

The spelling of 22165552161 in words is "twenty-two billion, one hundred sixty-five million, five hundred fifty-two thousand, one hundred sixty-one".