18187223 has 2 divisors, whose sum is σ = 18187224. Its totient is φ = 18187222.

The previous prime is 18187219. The next prime is 18187243. The reversal of 18187223 is 32278181.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18187223 - 2² = 18187219 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18187223.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18187243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9093611 + 9093612.

It is an arithmetic number, because the mean of its divisors is an integer number (9093612).

Almost surely, 2^18187223 is an apocalyptic number.

18187223 is a deficient number, since it is larger than the sum of its proper divisors (1).

18187223 is an equidigital number, since it uses as much as digits as its factorization.

18187223 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5376, while the sum is 32.

The square root of 18187223 is about 4264.6480511292. The cubic root of 18187223 is about 262.9796424845.

The spelling of 18187223 in words is "eighteen million, one hundred eighty-seven thousand, two hundred twenty-three".