18081313 has 2 divisors, whose sum is σ = 18081314. Its totient is φ = 18081312.

The previous prime is 18081311. The next prime is 18081337. The reversal of 18081313 is 31318081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11614464 + 6466849 = 3408^2 + 2543^2 .

It is a cyclic number.

It is not a de Polignac number, because 18081313 - 2¹ = 18081311 is a prime.

Together with 18081311, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18081311) 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, 9040656 + 9040657.

It is an arithmetic number, because the mean of its divisors is an integer number (9040657).

Almost surely, 2^18081313 is an apocalyptic number.

It is an amenable number.

18081313 is a deficient number, since it is larger than the sum of its proper divisors (1).

18081313 is an equidigital number, since it uses as much as digits as its factorization.

18081313 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 18081313 is about 4252.2127181034. The cubic root of 18081313 is about 262.4681769434.

Adding to 18081313 its reverse (31318081), we get a palindrome (49399394).

The spelling of 18081313 in words is "eighteen million, eighty-one thousand, three hundred thirteen".