166009957 has 4 divisors (see below), whose sum is σ = 168284140. Its totient is φ = 163735776.

The previous prime is 166009933. The next prime is 166009997. The reversal of 166009957 is 759900661.

166009957 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 759900661 = 13 ⋅58453897.

It can be written as a sum of positive squares in 2 ways, for example, as 67881121 + 98128836 = 8239^2 + 9906^2 .

It is a cyclic number.

It is not a de Polignac number, because 166009957 - 2⁷ = 166009829 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 (166009927) 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, 1136982 + ... + 1137127.

It is an arithmetic number, because the mean of its divisors is an integer number (42071035).

Almost surely, 2^166009957 is an apocalyptic number.

It is an amenable number.

166009957 is a deficient number, since it is larger than the sum of its proper divisors (2274183).

166009957 is an equidigital number, since it uses as much as digits as its factorization.

166009957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2274182.

The product of its (nonzero) digits is 102060, while the sum is 43.

The square root of 166009957 is about 12884.4851274702. The cubic root of 166009957 is about 549.5974542084.

The spelling of 166009957 in words is "one hundred sixty-six million, nine thousand, nine hundred fifty-seven".