18156211 has 2 divisors, whose sum is σ = 18156212. Its totient is φ = 18156210.

The previous prime is 18156209. The next prime is 18156227. The reversal of 18156211 is 11265181.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18156211 - 2¹ = 18156209 is a prime.

Together with 18156209, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (18156251) 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, 9078105 + 9078106.

It is an arithmetic number, because the mean of its divisors is an integer number (9078106).

Almost surely, 2^18156211 is an apocalyptic number.

18156211 is a deficient number, since it is larger than the sum of its proper divisors (1).

18156211 is an equidigital number, since it uses as much as digits as its factorization.

18156211 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 480, while the sum is 25.

The square root of 18156211 is about 4261.0105608881. The cubic root of 18156211 is about 262.8300839264.

The spelling of 18156211 in words is "eighteen million, one hundred fifty-six thousand, two hundred eleven".