18159666 has 16 divisors (see below), whose sum is σ = 41507904. Its totient is φ = 5188464.

The previous prime is 18159643. The next prime is 18159671. The reversal of 18159666 is 66695181.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 432373 = 18159666 / (1 + 8 + 1 + 5 + 9 + 6 + 6 + 6).

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, 216145 + ... + 216228.

It is an arithmetic number, because the mean of its divisors is an integer number (2594244).

Almost surely, 2^18159666 is an apocalyptic number.

18159666 is an abundant number, since it is smaller than the sum of its proper divisors (23348238).

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

18159666 is a wasteful number, since it uses less digits than its factorization.

18159666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 432385.

The product of its digits is 77760, while the sum is 42.

The square root of 18159666 is about 4261.4159618606. The cubic root of 18159666 is about 262.8467544447.

The spelling of 18159666 in words is "eighteen million, one hundred fifty-nine thousand, six hundred sixty-six".