166918109 has 2 divisors, whose sum is σ = 166918110. Its totient is φ = 166918108.

The previous prime is 166918099. The next prime is 166918123. The reversal of 166918109 is 901819661.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 96727225 + 70190884 = 9835^2 + 8378^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166918109 is a prime.

It is a super-2 number, since 2×166918109² = 55723310224271762, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166915109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83459054 + 83459055.

It is an arithmetic number, because the mean of its divisors is an integer number (83459055).

Almost surely, 2^166918109 is an apocalyptic number.

It is an amenable number.

166918109 is a deficient number, since it is larger than the sum of its proper divisors (1).

166918109 is an equidigital number, since it uses as much as digits as its factorization.

166918109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 41.

The square root of 166918109 is about 12919.6791368826. The cubic root of 166918109 is about 550.5978171906.

The spelling of 166918109 in words is "one hundred sixty-six million, nine hundred eighteen thousand, one hundred nine".