18406199 has 4 divisors (see below), whose sum is σ = 21035664. Its totient is φ = 15776736.

The previous prime is 18406183. The next prime is 18406229. The reversal of 18406199 is 99160481.

It is a happy number.

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 18406199 - 2⁴ = 18406183 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 (18406109) 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, 1314722 + ... + 1314735.

It is an arithmetic number, because the mean of its divisors is an integer number (5258916).

Almost surely, 2^18406199 is an apocalyptic number.

18406199 is a deficient number, since it is larger than the sum of its proper divisors (2629465).

18406199 is an equidigital number, since it uses as much as digits as its factorization.

18406199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2629464.

The product of its (nonzero) digits is 15552, while the sum is 38.

The square root of 18406199 is about 4290.2446317197. The cubic root of 18406199 is about 264.0308685592.

The spelling of 18406199 in words is "eighteen million, four hundred six thousand, one hundred ninety-nine".