18015139 has 2 divisors, whose sum is σ = 18015140. Its totient is φ = 18015138.

The previous prime is 18015091. The next prime is 18015149. The reversal of 18015139 is 93151081.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18015139 - 2¹¹ = 18013091 is a prime.

It is not a weakly prime, because it can be changed into another prime (18015149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9007569 + 9007570.

It is an arithmetic number, because the mean of its divisors is an integer number (9007570).

Almost surely, 2^18015139 is an apocalyptic number.

18015139 is a deficient number, since it is larger than the sum of its proper divisors (1).

18015139 is an equidigital number, since it uses as much as digits as its factorization.

18015139 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1080, while the sum is 28.

The square root of 18015139 is about 4244.4244603951. The cubic root of 18015139 is about 262.1475918025.

The spelling of 18015139 in words is "eighteen million, fifteen thousand, one hundred thirty-nine".