18156091 has 2 divisors, whose sum is σ = 18156092. Its totient is φ = 18156090.

The previous prime is 18156079. The next prime is 18156107. The reversal of 18156091 is 19065181.

It is a weak prime.

It is an emirp because it is prime and its reverse (19065181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18156091 - 2¹⁵ = 18123323 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18154091) 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, 9078045 + 9078046.

It is an arithmetic number, because the mean of its divisors is an integer number (9078046).

Almost surely, 2^18156091 is an apocalyptic number.

18156091 is a deficient number, since it is larger than the sum of its proper divisors (1).

18156091 is an equidigital number, since it uses as much as digits as its factorization.

18156091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 31.

The square root of 18156091 is about 4260.9964796981. The cubic root of 18156091 is about 262.8295048834.

The spelling of 18156091 in words is "eighteen million, one hundred fifty-six thousand, ninety-one".