165363561 has 18 divisors (see below), whose sum is σ = 262548650. Its totient is φ = 100219680.

The previous prime is 165363559. The next prime is 165363577.

165363561 is a `hidden beast` number, since 1 + 65 + 36 + 3 + 561 = 666.

165363561 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in only one way, i.e., 102637161 + 62726400 = 10131^2 + 7920^2 .

It is not a de Polignac number, because 165363561 - 2¹ = 165363559 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (165363581) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 74836 + ... + 77013.

Almost surely, 2^165363561 is an apocalyptic number.

165363561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

165363561 is a deficient number, since it is larger than the sum of its proper divisors (97185089).

165363561 is a wasteful number, since it uses less digits than its factorization.

165363561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151877 (or 151863 counting only the distinct ones).

The product of its digits is 48600, while the sum is 36.

The square root of 165363561 is about 12859.3763845686. The cubic root of 165363561 is about 548.8832004904.

The spelling of 165363561 in words is "one hundred sixty-five million, three hundred sixty-three thousand, five hundred sixty-one".