18231313 has 2 divisors, whose sum is σ = 18231314. Its totient is φ = 18231312.

The previous prime is 18231281. The next prime is 18231331. The reversal of 18231313 is 31313281.

Together with next prime (18231331) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17909824 + 321489 = 4232^2 + 567^2 .

It is a cyclic number.

It is not a de Polignac number, because 18231313 - 2⁵ = 18231281 is a prime.

It is not a weakly prime, because it can be changed into another prime (18231373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9115656 + 9115657.

It is an arithmetic number, because the mean of its divisors is an integer number (9115657).

Almost surely, 2^18231313 is an apocalyptic number.

It is an amenable number.

18231313 is a deficient number, since it is larger than the sum of its proper divisors (1).

18231313 is an equidigital number, since it uses as much as digits as its factorization.

18231313 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 22.

The square root of 18231313 is about 4269.8141645744. The cubic root of 18231313 is about 263.1919786499.

Adding to 18231313 its reverse (31313281), we get a palindrome (49544594).

It can be divided in two parts, 1823 and 1313, that added together give a square (3136 = 56²).

The spelling of 18231313 in words is "eighteen million, two hundred thirty-one thousand, three hundred thirteen".