170861 has 4 divisors (see below), whose sum is σ = 173724. Its totient is φ = 168000.

The previous prime is 170857. The next prime is 170873. The reversal of 170861 is 168071.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 37636 + 133225 = 194^2 + 365^2 .

It is a cyclic number.

It is not a de Polignac number, because 170861 - 2² = 170857 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (170801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1340 + ... + 1461.

It is an arithmetic number, because the mean of its divisors is an integer number (43431).

2¹⁷⁰⁸⁶¹ is an apocalyptic number.

It is an amenable number.

170861 is a deficient number, since it is larger than the sum of its proper divisors (2863).

170861 is an equidigital number, since it uses as much as digits as its factorization.

170861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2862.

The product of its (nonzero) digits is 336, while the sum is 23.

The square root of 170861 is about 413.3533597299. The cubic root of 170861 is about 55.4899475882.

The spelling of 170861 in words is "one hundred seventy thousand, eight hundred sixty-one".