166261223 has 4 divisors (see below), whose sum is σ = 168538848. Its totient is φ = 163983600.

The previous prime is 166261213. The next prime is 166261243. The reversal of 166261223 is 322162661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 322162661 = 113 ⋅2850997.

It is a cyclic number.

It is not a de Polignac number, because 166261223 - 2²⁴ = 149484007 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 (166261213) 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, 1138703 + ... + 1138848.

It is an arithmetic number, because the mean of its divisors is an integer number (42134712).

Almost surely, 2^166261223 is an apocalyptic number.

166261223 is a deficient number, since it is larger than the sum of its proper divisors (2277625).

166261223 is an equidigital number, since it uses as much as digits as its factorization.

166261223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2277624.

The product of its digits is 5184, while the sum is 29.

The square root of 166261223 is about 12894.2321601560. The cubic root of 166261223 is about 549.8745973051.

The spelling of 166261223 in words is "one hundred sixty-six million, two hundred sixty-one thousand, two hundred twenty-three".