18307229 has 2 divisors, whose sum is σ = 18307230. Its totient is φ = 18307228.

The previous prime is 18307217. The next prime is 18307231. The reversal of 18307229 is 92270381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15031129 + 3276100 = 3877^2 + 1810^2 .

It is a cyclic number.

It is not a de Polignac number, because 18307229 - 2⁸ = 18306973 is a prime.

Together with 18307231, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 18307195 and 18307204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18307129) 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, 9153614 + 9153615.

It is an arithmetic number, because the mean of its divisors is an integer number (9153615).

Almost surely, 2^18307229 is an apocalyptic number.

It is an amenable number.

18307229 is a deficient number, since it is larger than the sum of its proper divisors (1).

18307229 is an equidigital number, since it uses as much as digits as its factorization.

18307229 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 18307229 is about 4278.6947776162. The cubic root of 18307229 is about 263.5567871348.

The spelling of 18307229 in words is "eighteen million, three hundred seven thousand, two hundred twenty-nine".