166623631 has 4 divisors (see below), whose sum is σ = 170687664. Its totient is φ = 162559600.

The previous prime is 166623623. The next prime is 166623643. The reversal of 166623631 is 136326661.

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 166623631 - 2³ = 166623623 is a prime.

It is a super-2 number, since 2×166623631² = 55526868815248322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166623671) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2031955 + ... + 2032036.

It is an arithmetic number, because the mean of its divisors is an integer number (42671916).

Almost surely, 2^166623631 is an apocalyptic number.

166623631 is a deficient number, since it is larger than the sum of its proper divisors (4064033).

166623631 is an equidigital number, since it uses as much as digits as its factorization.

166623631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4064032.

The product of its digits is 23328, while the sum is 34.

The square root of 166623631 is about 12908.2776155458. The cubic root of 166623631 is about 550.2738371914.

The spelling of 166623631 in words is "one hundred sixty-six million, six hundred twenty-three thousand, six hundred thirty-one".