18091668 has 48 divisors (see below), whose sum is σ = 49556864. Its totient is φ = 5028480.

The previous prime is 18091657. The next prime is 18091669. The reversal of 18091668 is 86619081.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18091669) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 198 + ... + 6018.

Almost surely, 2^18091668 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18091668, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24778432).

18091668 is an abundant number, since it is smaller than the sum of its proper divisors (31465196).

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

18091668 is a wasteful number, since it uses less digits than its factorization.

18091668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5872 (or 5870 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 39.

The square root of 18091668 is about 4253.4301451887. The cubic root of 18091668 is about 262.5182717440.

The spelling of 18091668 in words is "eighteen million, ninety-one thousand, six hundred sixty-eight".