166558361 has 4 divisors (see below), whose sum is σ = 166727424. Its totient is φ = 166389300.

The previous prime is 166558331. The next prime is 166558391. The reversal of 166558361 is 163855661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 163855661 = 883 ⋅185567.

It is an interprime number because it is at equal distance from previous prime (166558331) and next prime (166558391).

It is a cyclic number.

It is not a de Polignac number, because 166558361 - 2¹⁰ = 166557337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166558321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83045 + ... + 85026.

It is an arithmetic number, because the mean of its divisors is an integer number (41681856).

Almost surely, 2^166558361 is an apocalyptic number.

It is an amenable number.

166558361 is a deficient number, since it is larger than the sum of its proper divisors (169063).

166558361 is an equidigital number, since it uses as much as digits as its factorization.

166558361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169062.

The product of its digits is 129600, while the sum is 41.

The square root of 166558361 is about 12905.7491452453. The cubic root of 166558361 is about 550.2019765078.

The spelling of 166558361 in words is "one hundred sixty-six million, five hundred fifty-eight thousand, three hundred sixty-one".