18138611 has 2 divisors, whose sum is σ = 18138612. Its totient is φ = 18138610.

The previous prime is 18138599. The next prime is 18138613. The reversal of 18138611 is 11683181.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18138611 is a prime.

Together with 18138613, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_1159580 and since 18138611 and 1159580 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (18138613) 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, 9069305 + 9069306.

It is an arithmetic number, because the mean of its divisors is an integer number (9069306).

Almost surely, 2^18138611 is an apocalyptic number.

18138611 is a deficient number, since it is larger than the sum of its proper divisors (1).

18138611 is an equidigital number, since it uses as much as digits as its factorization.

18138611 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 29.

The square root of 18138611 is about 4258.9448223709. The cubic root of 18138611 is about 262.7451303535.

The spelling of 18138611 in words is "eighteen million, one hundred thirty-eight thousand, six hundred eleven".