18398666 has 32 divisors (see below), whose sum is σ = 33844608. Its totient is φ = 7381440.

The previous prime is 18398659. The next prime is 18398671. The reversal of 18398666 is 66689381.

It is a self number, because there is not a number n which added to its sum of digits gives 18398666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5180 + ... + 7976.

It is an arithmetic number, because the mean of its divisors is an integer number (1057644).

Almost surely, 2^18398666 is an apocalyptic number.

18398666 is a deficient number, since it is larger than the sum of its proper divisors (15445942).

18398666 is a wasteful number, since it uses less digits than its factorization.

18398666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2846.

The product of its digits is 373248, while the sum is 47.

The square root of 18398666 is about 4289.3666199102. The cubic root of 18398666 is about 263.9948441754.

The spelling of 18398666 in words is "eighteen million, three hundred ninety-eight thousand, six hundred sixty-six".