18217159 has 2 divisors, whose sum is σ = 18217160. Its totient is φ = 18217158.

The previous prime is 18217141. The next prime is 18217189. The reversal of 18217159 is 95171281.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18217159 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18217189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9108579 + 9108580.

It is an arithmetic number, because the mean of its divisors is an integer number (9108580).

Almost surely, 2^18217159 is an apocalyptic number.

18217159 is a deficient number, since it is larger than the sum of its proper divisors (1).

18217159 is an equidigital number, since it uses as much as digits as its factorization.

18217159 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 34.

The square root of 18217159 is about 4268.1563935732. The cubic root of 18217159 is about 263.1238507406.

The spelling of 18217159 in words is "eighteen million, two hundred seventeen thousand, one hundred fifty-nine".