166831 has 4 divisors (see below), whose sum is σ = 190672. Its totient is φ = 142992.

The previous prime is 166823. The next prime is 166841. The reversal of 166831 is 138661.

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

It is a cyclic number.

It is not a de Polignac number, because 166831 - 2³ = 166823 is a prime.

It is a super-2 number, since 2×166831² = 55665165122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 166796 and 166805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166841) 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, 11910 + ... + 11923.

It is an arithmetic number, because the mean of its divisors is an integer number (47668).

2¹⁶⁶⁸³¹ is an apocalyptic number.

166831 is a deficient number, since it is larger than the sum of its proper divisors (23841).

166831 is an equidigital number, since it uses as much as digits as its factorization.

166831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23840.

The product of its digits is 864, while the sum is 25.

The square root of 166831 is about 408.4495072833. The cubic root of 166831 is about 55.0502020972.

The spelling of 166831 in words is "one hundred sixty-six thousand, eight hundred thirty-one".