18706431 has 16 divisors (see below), whose sum is σ = 26364800. Its totient is φ = 11765088.

The previous prime is 18706427. The next prime is 18706439. The reversal of 18706431 is 13460781.

It is a happy number.

It is not a de Polignac number, because 18706431 - 2² = 18706427 is a prime.

It is a super-2 number, since 2×18706431² = 699861121515522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18706439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16965 + ... + 18033.

It is an arithmetic number, because the mean of its divisors is an integer number (1647800).

Almost surely, 2^18706431 is an apocalyptic number.

18706431 is a deficient number, since it is larger than the sum of its proper divisors (7658369).

18706431 is a wasteful number, since it uses less digits than its factorization.

18706431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1398.

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 18706431 is about 4325.0931781870. The cubic root of 18706431 is about 265.4587095005.

The spelling of 18706431 in words is "eighteen million, seven hundred six thousand, four hundred thirty-one".