166390099 has 4 divisors (see below), whose sum is σ = 166531464. Its totient is φ = 166248736.

The previous prime is 166390097. The next prime is 166390109. The reversal of 166390099 is 990093661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 990093661 = 28843 ⋅34327.

It is a cyclic number.

It is not a de Polignac number, because 166390099 - 2¹ = 166390097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166390097) 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, 68902 + ... + 71275.

It is an arithmetic number, because the mean of its divisors is an integer number (41632866).

Almost surely, 2^166390099 is an apocalyptic number.

166390099 is a deficient number, since it is larger than the sum of its proper divisors (141365).

166390099 is a wasteful number, since it uses less digits than its factorization.

166390099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141364.

The product of its (nonzero) digits is 78732, while the sum is 43.

The square root of 166390099 is about 12899.2286203478. The cubic root of 166390099 is about 550.0166375132.

The spelling of 166390099 in words is "one hundred sixty-six million, three hundred ninety thousand, ninety-nine".