18666660 has 24 divisors (see below), whose sum is σ = 52266816. Its totient is φ = 4977760.

The previous prime is 18666647. The next prime is 18666667. The reversal of 18666660 is 6666681.

It is not an unprimeable number, because it can be changed into a prime (18666667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 155496 + ... + 155615.

It is an arithmetic number, because the mean of its divisors is an integer number (2177784).

Almost surely, 2^18666660 is an apocalyptic number.

18666660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18666660 is an abundant number, since it is smaller than the sum of its proper divisors (33600156).

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

18666660 is a wasteful number, since it uses less digits than its factorization.

18666660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311123 (or 311121 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 39.

The square root of 18666660 is about 4320.4930274218. The cubic root of 18666660 is about 265.2704489466.

The spelling of 18666660 in words is "eighteen million, six hundred sixty-six thousand, six hundred sixty".