18218329 has 2 divisors, whose sum is σ = 18218330. Its totient is φ = 18218328.

The previous prime is 18218327. The next prime is 18218357. The reversal of 18218329 is 92381281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15784729 + 2433600 = 3973^2 + 1560^2 .

It is a cyclic number.

It is not a de Polignac number, because 18218329 - 2¹ = 18218327 is a prime.

Together with 18218327, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 18218294 and 18218303.

It is not a weakly prime, because it can be changed into another prime (18218327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9109164 + 9109165.

It is an arithmetic number, because the mean of its divisors is an integer number (9109165).

Almost surely, 2^18218329 is an apocalyptic number.

It is an amenable number.

18218329 is a deficient number, since it is larger than the sum of its proper divisors (1).

18218329 is an equidigital number, since it uses as much as digits as its factorization.

18218329 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6912, while the sum is 34.

The square root of 18218329 is about 4268.2934528919. The cubic root of 18218329 is about 263.1294836774.

The spelling of 18218329 in words is "eighteen million, two hundred eighteen thousand, three hundred twenty-nine".