18099431 has 16 divisors (see below), whose sum is σ = 21356544. Its totient is φ = 15017184.

The previous prime is 18099379. The next prime is 18099437. The reversal of 18099431 is 13499081.

It is a de Polignac number, because none of the positive numbers 2^k-18099431 is a prime.

It is a super-2 number, since 2×18099431² = 655178805047522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18099391 and 18099400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18099437) 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, 47066 + ... + 47448.

It is an arithmetic number, because the mean of its divisors is an integer number (1334784).

Almost surely, 2^18099431 is an apocalyptic number.

18099431 is a deficient number, since it is larger than the sum of its proper divisors (3257113).

18099431 is a wasteful number, since it uses less digits than its factorization.

18099431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 590.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 18099431 is about 4254.3426049156. The cubic root of 18099431 is about 262.5558145865. Note that the first 3 decimals are identical.

The spelling of 18099431 in words is "eighteen million, ninety-nine thousand, four hundred thirty-one".