18181013 has 2 divisors, whose sum is σ = 18181014. Its totient is φ = 18181012.

The previous prime is 18180991. The next prime is 18181021. The reversal of 18181013 is 31018181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15382084 + 2798929 = 3922^2 + 1673^2 .

It is a cyclic number.

It is not a de Polignac number, because 18181013 - 2¹⁶ = 18115477 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18181013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18181213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9090506 + 9090507.

It is an arithmetic number, because the mean of its divisors is an integer number (9090507).

Almost surely, 2^18181013 is an apocalyptic number.

It is an amenable number.

18181013 is a deficient number, since it is larger than the sum of its proper divisors (1).

18181013 is an equidigital number, since it uses as much as digits as its factorization.

18181013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 23.

The square root of 18181013 is about 4263.9199101296. The cubic root of 18181013 is about 262.9497077424.

Adding to 18181013 its reverse (31018181), we get a palindrome (49199194).

The spelling of 18181013 in words is "eighteen million, one hundred eighty-one thousand, thirteen".