166118399 has 4 divisors (see below), whose sum is σ = 166282440. Its totient is φ = 165954360.

The previous prime is 166118389. The next prime is 166118423. The reversal of 166118399 is 993811661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 993811661 = 449 ⋅2213389.

It is a cyclic number.

It is not a de Polignac number, because 166118399 - 2¹⁶ = 166052863 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 (166118389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 80492 + ... + 82529.

It is an arithmetic number, because the mean of its divisors is an integer number (41570610).

Almost surely, 2^166118399 is an apocalyptic number.

166118399 is a deficient number, since it is larger than the sum of its proper divisors (164041).

166118399 is a wasteful number, since it uses less digits than its factorization.

166118399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164040.

The product of its digits is 69984, while the sum is 44.

The square root of 166118399 is about 12888.6926800200. The cubic root of 166118399 is about 549.7170985872.

The spelling of 166118399 in words is "one hundred sixty-six million, one hundred eighteen thousand, three hundred ninety-nine".