18156139 has 2 divisors, whose sum is σ = 18156140. Its totient is φ = 18156138.

The previous prime is 18156137. The next prime is 18156143. The reversal of 18156139 is 93165181.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18156139 - 2¹ = 18156137 is a prime.

Together with 18156137, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18156133) 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, 9078069 + 9078070.

It is an arithmetic number, because the mean of its divisors is an integer number (9078070).

Almost surely, 2^18156139 is an apocalyptic number.

18156139 is a deficient number, since it is larger than the sum of its proper divisors (1).

18156139 is an equidigital number, since it uses as much as digits as its factorization.

18156139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6480, while the sum is 34.

The square root of 18156139 is about 4261.0021121797. The cubic root of 18156139 is about 262.8297365009.

The spelling of 18156139 in words is "eighteen million, one hundred fifty-six thousand, one hundred thirty-nine".