166213623 has 4 divisors (see below), whose sum is σ = 221618168. Its totient is φ = 110809080.

The previous prime is 166213601. The next prime is 166213637. The reversal of 166213623 is 326312661.

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

It is not a de Polignac number, because 166213623 - 2⁵ = 166213591 is a prime.

It is a super-2 number, since 2×166213623² = 55253936941572258, 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 (166213643) 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, 27702268 + ... + 27702273.

It is an arithmetic number, because the mean of its divisors is an integer number (55404542).

Almost surely, 2^166213623 is an apocalyptic number.

166213623 is a deficient number, since it is larger than the sum of its proper divisors (55404545).

166213623 is an equidigital number, since it uses as much as digits as its factorization.

166213623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55404544.

The product of its digits is 7776, while the sum is 30.

The square root of 166213623 is about 12892.3862414993. The cubic root of 166213623 is about 549.8221165790.

The spelling of 166213623 in words is "one hundred sixty-six million, two hundred thirteen thousand, six hundred twenty-three".