168561 has 10 divisors (see below), whose sum is σ = 251922. Its totient is φ = 112320.

The previous prime is 168559. The next prime is 168599. The reversal of 168561 is 165861.

It can be written as a sum of positive squares in only one way, i.e., 136161 + 32400 = 369^2 + 180^2 .

It is not a de Polignac number, because 168561 - 2¹ = 168559 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (168541) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 960 + ... + 1121.

2¹⁶⁸⁵⁶¹ is an apocalyptic number.

It is an amenable number.

168561 is a deficient number, since it is larger than the sum of its proper divisors (83361).

168561 is an equidigital number, since it uses as much as digits as its factorization.

168561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2093 (or 2084 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 168561 is about 410.5618102065. The cubic root of 168561 is about 55.2398341963.

It can be divided in two parts, 168 and 561, that added together give a 6-th power (729 = 3⁶).

The spelling of 168561 in words is "one hundred sixty-eight thousand, five hundred sixty-one".