18138613 has 2 divisors, whose sum is σ = 18138614. Its totient is φ = 18138612.

The previous prime is 18138611. The next prime is 18138623. The reversal of 18138613 is 31683181.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10614564 + 7524049 = 3258^2 + 2743^2 .

It is an emirp because it is prime and its reverse (31683181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18138613 - 2¹ = 18138611 is a prime.

Together with 18138611, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18138611) 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, 9069306 + 9069307.

It is an arithmetic number, because the mean of its divisors is an integer number (9069307).

Almost surely, 2^18138613 is an apocalyptic number.

It is an amenable number.

18138613 is a deficient number, since it is larger than the sum of its proper divisors (1).

18138613 is an equidigital number, since it uses as much as digits as its factorization.

18138613 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3456, while the sum is 31.

The square root of 18138613 is about 4258.9450571708. The cubic root of 18138613 is about 262.7451400105.

The spelling of 18138613 in words is "eighteen million, one hundred thirty-eight thousand, six hundred thirteen".