18220091 has 8 divisors (see below), whose sum is σ = 19116000. Its totient is φ = 17342080.

The previous prime is 18220087. The next prime is 18220093. The reversal of 18220091 is 19002281.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18220091 - 2² = 18220087 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18220093) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2366 + ... + 6483.

It is an arithmetic number, because the mean of its divisors is an integer number (2389500).

Almost surely, 2^18220091 is an apocalyptic number.

18220091 is a deficient number, since it is larger than the sum of its proper divisors (895909).

18220091 is an equidigital number, since it uses as much as digits as its factorization.

18220091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8949.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 18220091 is about 4268.4998535785. The cubic root of 18220091 is about 263.1379663288.

The spelling of 18220091 in words is "eighteen million, two hundred twenty thousand, ninety-one".