166645243 has 4 divisors (see below), whose sum is σ = 172020928. Its totient is φ = 161269560.

The previous prime is 166645211. The next prime is 166645247. The reversal of 166645243 is 342546661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 166645243 - 2⁵ = 166645211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166645247) 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, 2687796 + ... + 2687857.

It is an arithmetic number, because the mean of its divisors is an integer number (43005232).

Almost surely, 2^166645243 is an apocalyptic number.

166645243 is a deficient number, since it is larger than the sum of its proper divisors (5375685).

166645243 is an equidigital number, since it uses as much as digits as its factorization.

166645243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5375684.

The product of its digits is 103680, while the sum is 37.

The square root of 166645243 is about 12909.1147256502. The cubic root of 166645243 is about 550.2976273425.

The spelling of 166645243 in words is "one hundred sixty-six million, six hundred forty-five thousand, two hundred forty-three".