18431013 has 4 divisors (see below), whose sum is σ = 24574688. Its totient is φ = 12287340.

The previous prime is 18431011. The next prime is 18431041. The reversal of 18431013 is 31013481.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 31013481 = 3 ⋅10337827.

It is not a de Polignac number, because 18431013 - 2¹ = 18431011 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 (18431011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3071833 + ... + 3071838.

It is an arithmetic number, because the mean of its divisors is an integer number (6143672).

Almost surely, 2^18431013 is an apocalyptic number.

It is an amenable number.

18431013 is a deficient number, since it is larger than the sum of its proper divisors (6143675).

18431013 is an equidigital number, since it uses as much as digits as its factorization.

18431013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6143674.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 18431013 is about 4293.1355673913. The cubic root of 18431013 is about 264.1494648358.

Adding to 18431013 its reverse (31013481), we get a palindrome (49444494).

The spelling of 18431013 in words is "eighteen million, four hundred thirty-one thousand, thirteen".