166018661 has 4 divisors (see below), whose sum is σ = 168357024. Its totient is φ = 163680300.

The previous prime is 166018621. The next prime is 166018673. The reversal of 166018661 is 166810661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 166018661 - 2¹⁰ = 166017637 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 (166018621) 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, 1169075 + ... + 1169216.

It is an arithmetic number, because the mean of its divisors is an integer number (42089256).

Almost surely, 2^166018661 is an apocalyptic number.

It is an amenable number.

166018661 is a deficient number, since it is larger than the sum of its proper divisors (2338363).

166018661 is an equidigital number, since it uses as much as digits as its factorization.

166018661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2338362.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 166018661 is about 12884.8228936218. The cubic root of 166018661 is about 549.6070592801.

The spelling of 166018661 in words is "one hundred sixty-six million, eighteen thousand, six hundred sixty-one".