664279918 has 4 divisors (see below), whose sum is σ = 996419880. Its totient is φ = 332139958.

The previous prime is 664279901. The next prime is 664279921. The reversal of 664279918 is 819972466.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166069978 + ... + 166069981.

It is an arithmetic number, because the mean of its divisors is an integer number (249104970).

Almost surely, 2^664279918 is an apocalyptic number.

664279918 is a deficient number, since it is larger than the sum of its proper divisors (332139962).

664279918 is a wasteful number, since it uses less digits than its factorization.

664279918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332139961.

The product of its digits is 1306368, while the sum is 52.

The square root of 664279918 is about 25773.6283437160. The cubic root of 664279918 is about 872.5367096483.

The spelling of 664279918 in words is "six hundred sixty-four million, two hundred seventy-nine thousand, nine hundred eighteen".