166890091 has 16 divisors (see below), whose sum is σ = 184296960. Its totient is φ = 150530400.

The previous prime is 166890089. The next prime is 166890103. The reversal of 166890091 is 190098661.

It is a cyclic number.

It is not a de Polignac number, because 166890091 - 2¹ = 166890089 is a prime.

It is a super-3 number, since 3×166890091³ (a number of 26 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (166890991) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30516 + ... + 35566.

It is an arithmetic number, because the mean of its divisors is an integer number (11518560).

Almost surely, 2^166890091 is an apocalyptic number.

166890091 is a deficient number, since it is larger than the sum of its proper divisors (17406869).

166890091 is a wasteful number, since it uses less digits than its factorization.

166890091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5154.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 166890091 is about 12918.5947765227. The cubic root of 166890091 is about 550.5670086443.

The spelling of 166890091 in words is "one hundred sixty-six million, eight hundred ninety thousand, ninety-one".