18711139 has 2 divisors, whose sum is σ = 18711140. Its totient is φ = 18711138.

The previous prime is 18711137. The next prime is 18711163. The reversal of 18711139 is 93111781.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18711139 - 2¹ = 18711137 is a prime.

Together with 18711137, it forms a pair of twin primes.

It is equal to p_1193791 and since 18711139 and 1193791 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18711139.

It is not a weakly prime, because it can be changed into another prime (18711131) 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, 9355569 + 9355570.

It is an arithmetic number, because the mean of its divisors is an integer number (9355570).

Almost surely, 2^18711139 is an apocalyptic number.

18711139 is a deficient number, since it is larger than the sum of its proper divisors (1).

18711139 is an equidigital number, since it uses as much as digits as its factorization.

18711139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1512, while the sum is 31.

The square root of 18711139 is about 4325.6374096773. The cubic root of 18711139 is about 265.4809776851.

The spelling of 18711139 in words is "eighteen million, seven hundred eleven thousand, one hundred thirty-nine".