18321668 has 6 divisors (see below), whose sum is σ = 32062926. Its totient is φ = 9160832.

The previous prime is 18321661. The next prime is 18321673. The reversal of 18321668 is 86612381.

It can be written as a sum of positive squares in only one way, i.e., 16662724 + 1658944 = 4082^2 + 1288^2 .

It is not an unprimeable number, because it can be changed into a prime (18321661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2290205 + ... + 2290212.

It is an arithmetic number, because the mean of its divisors is an integer number (5343821).

Almost surely, 2^18321668 is an apocalyptic number.

It is an amenable number.

18321668 is a deficient number, since it is larger than the sum of its proper divisors (13741258).

18321668 is a wasteful number, since it uses less digits than its factorization.

18321668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4580421 (or 4580419 counting only the distinct ones).

The product of its digits is 13824, while the sum is 35.

The square root of 18321668 is about 4280.3817586753. The cubic root of 18321668 is about 263.6260584305.

The spelling of 18321668 in words is "eighteen million, three hundred twenty-one thousand, six hundred sixty-eight".