166638313 has 4 divisors (see below), whose sum is σ = 169125520. Its totient is φ = 164151108.

The previous prime is 166638293. The next prime is 166638317. The reversal of 166638313 is 313836661.

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.

It is a cyclic number.

It is not a de Polignac number, because 166638313 - 2⁵ = 166638281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166638317) 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, 1243503 + ... + 1243636.

It is an arithmetic number, because the mean of its divisors is an integer number (42281380).

Almost surely, 2^166638313 is an apocalyptic number.

It is an amenable number.

166638313 is a deficient number, since it is larger than the sum of its proper divisors (2487207).

166638313 is an equidigital number, since it uses as much as digits as its factorization.

166638313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2487206.

The product of its digits is 46656, while the sum is 37.

The square root of 166638313 is about 12908.8463078619. The cubic root of 166638313 is about 550.2899991311.

It can be divided in two parts, 16663 and 8313, that added together give a triangular number (24976 = T₂₂₃).

The spelling of 166638313 in words is "one hundred sixty-six million, six hundred thirty-eight thousand, three hundred thirteen".