171561 has 16 divisors (see below), whose sum is σ = 254016. Its totient is φ = 102336.

The previous prime is 171559. The next prime is 171571. The reversal of 171561 is 165171.

171561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 171561 - 2¹ = 171559 is a prime.

It is not an unprimeable number, because it can be changed into a prime (171541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2026 + ... + 2108.

It is an arithmetic number, because the mean of its divisors is an integer number (15876).

2¹⁷¹⁵⁶¹ is an apocalyptic number.

It is an amenable number.

171561 is a deficient number, since it is larger than the sum of its proper divisors (82455).

171561 is a wasteful number, since it uses less digits than its factorization.

171561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152.

The product of its digits is 210, while the sum is 21.

The square root of 171561 is about 414.1992274256. The cubic root of 171561 is about 55.5656232125.

The spelling of 171561 in words is "one hundred seventy-one thousand, five hundred sixty-one".