166664638 has 16 divisors (see below), whose sum is σ = 286399584. Its totient is φ = 71255520.

The previous prime is 166664633. The next prime is 166664677. The reversal of 166664638 is 836466661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166664633) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8245 + ... + 20032.

It is an arithmetic number, because the mean of its divisors is an integer number (17899974).

Almost surely, 2^166664638 is an apocalyptic number.

166664638 is a deficient number, since it is larger than the sum of its proper divisors (119734946).

166664638 is a wasteful number, since it uses less digits than its factorization.

166664638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28707.

The product of its digits is 746496, while the sum is 46.

The square root of 166664638 is about 12909.8659171968. The cubic root of 166664638 is about 550.3189753035.

The spelling of 166664638 in words is "one hundred sixty-six million, six hundred sixty-four thousand, six hundred thirty-eight".