18431249 has 2 divisors, whose sum is σ = 18431250. Its totient is φ = 18431248.

The previous prime is 18431243. The next prime is 18431251. The reversal of 18431249 is 94213481.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16974400 + 1456849 = 4120^2 + 1207^2 .

It is a cyclic number.

It is not a de Polignac number, because 18431249 - 2⁴ = 18431233 is a prime.

It is a Sophie Germain prime.

Together with 18431251, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (18431243) 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 as a sum of consecutive naturals, namely, 9215624 + 9215625.

It is an arithmetic number, because the mean of its divisors is an integer number (9215625).

Almost surely, 2^18431249 is an apocalyptic number.

It is an amenable number.

18431249 is a deficient number, since it is larger than the sum of its proper divisors (1).

18431249 is an equidigital number, since it uses as much as digits as its factorization.

18431249 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6912, while the sum is 32.

The square root of 18431249 is about 4293.1630530414. The cubic root of 18431249 is about 264.1505922654.

The spelling of 18431249 in words is "eighteen million, four hundred thirty-one thousand, two hundred forty-nine".