165561363 has 12 divisors (see below), whose sum is σ = 260884728. Its totient is φ = 100340160.

The previous prime is 165561353. The next prime is 165561379. The reversal of 165561363 is 363165561.

165561363 is a `hidden beast` number, since 1 + 65 + 561 + 36 + 3 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-165561363 is a prime.

It is not an unprimeable number, because it can be changed into a prime (165561343) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 836070 + ... + 836267.

It is an arithmetic number, because the mean of its divisors is an integer number (21740394).

Almost surely, 2^165561363 is an apocalyptic number.

165561363 is a deficient number, since it is larger than the sum of its proper divisors (95323365).

165561363 is a wasteful number, since it uses less digits than its factorization.

165561363 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1672354 (or 1672351 counting only the distinct ones).

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

The square root of 165561363 is about 12867.0650499638. The cubic root of 165561363 is about 549.1019647970.

The spelling of 165561363 in words is "one hundred sixty-five million, five hundred sixty-one thousand, three hundred sixty-three".