66664518 has 16 divisors (see below), whose sum is σ = 136166400. Its totient is φ = 21748616.

The previous prime is 66664487. The next prime is 66664523. The reversal of 66664518 is 81546666.

It is a self number, because there is not a number n which added to its sum of digits gives 66664518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 117918 + ... + 118481.

It is an arithmetic number, because the mean of its divisors is an integer number (8510400).

Almost surely, 2^66664518 is an apocalyptic number.

66664518 is an abundant number, since it is smaller than the sum of its proper divisors (69501882).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66664518 is a wasteful number, since it uses less digits than its factorization.

66664518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 236451.

The product of its digits is 207360, while the sum is 42.

The square root of 66664518 is about 8164.8342297930. The cubic root of 66664518 is about 405.4757767832.

The spelling of 66664518 in words is "sixty-six million, six hundred sixty-four thousand, five hundred eighteen".