18231113 has 2 divisors, whose sum is σ = 18231114. Its totient is φ = 18231112.

The previous prime is 18231091. The next prime is 18231119. The reversal of 18231113 is 31113281.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16949689 + 1281424 = 4117^2 + 1132^2 .

It is a cyclic number.

It is not a de Polignac number, because 18231113 - 2⁶ = 18231049 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (18231119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9115556 + 9115557.

It is an arithmetic number, because the mean of its divisors is an integer number (9115557).

Almost surely, 2^18231113 is an apocalyptic number.

It is an amenable number.

18231113 is a deficient number, since it is larger than the sum of its proper divisors (1).

18231113 is an equidigital number, since it uses as much as digits as its factorization.

18231113 is an evil number, because the sum of its binary digits is even.

The product of its digits is 144, while the sum is 20.

The square root of 18231113 is about 4269.7907442871. The cubic root of 18231113 is about 263.1910162290.

Adding to 18231113 its reverse (31113281), we get a palindrome (49344394).

The spelling of 18231113 in words is "eighteen million, two hundred thirty-one thousand, one hundred thirteen".