166004431 has 4 divisors (see below), whose sum is σ = 166034664. Its totient is φ = 165974200.

The previous prime is 166004429. The next prime is 166004441. The reversal of 166004431 is 134400661.

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 166004431 - 2¹ = 166004429 is a prime.

It is a super-2 number, since 2×166004431² = 55114942223267522, 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 = 166004396 and 166004405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166004441) 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, 4300 + ... + 18721.

It is an arithmetic number, because the mean of its divisors is an integer number (41508666).

Almost surely, 2^166004431 is an apocalyptic number.

166004431 is a deficient number, since it is larger than the sum of its proper divisors (30233).

166004431 is an equidigital number, since it uses as much as digits as its factorization.

166004431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30232.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 166004431 is about 12884.2706817266. The cubic root of 166004431 is about 549.5913559612.

The spelling of 166004431 in words is "one hundred sixty-six million, four thousand, four hundred thirty-one".