18420199 has 4 divisors (see below), whose sum is σ = 21051664. Its totient is φ = 15788736.

The previous prime is 18420161. The next prime is 18420209. The reversal of 18420199 is 99102481.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18420199 - 2⁷ = 18420071 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18420119) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1315722 + ... + 1315735.

It is an arithmetic number, because the mean of its divisors is an integer number (5262916).

Almost surely, 2^18420199 is an apocalyptic number.

18420199 is a deficient number, since it is larger than the sum of its proper divisors (2631465).

18420199 is an equidigital number, since it uses as much as digits as its factorization.

18420199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2631464.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 18420199 is about 4291.8759301732. The cubic root of 18420199 is about 264.0977933919.

The spelling of 18420199 in words is "eighteen million, four hundred twenty thousand, one hundred ninety-nine".