18139229 has 2 divisors, whose sum is σ = 18139230. Its totient is φ = 18139228.

The previous prime is 18139217. The next prime is 18139237. The reversal of 18139229 is 92293181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18062500 + 76729 = 4250^2 + 277^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18139229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18139279) 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, 9069614 + 9069615.

It is an arithmetic number, because the mean of its divisors is an integer number (9069615).

Almost surely, 2^18139229 is an apocalyptic number.

It is an amenable number.

18139229 is a deficient number, since it is larger than the sum of its proper divisors (1).

18139229 is an equidigital number, since it uses as much as digits as its factorization.

18139229 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 35.

The square root of 18139229 is about 4259.0173749352. The cubic root of 18139229 is about 262.7481143131.

The spelling of 18139229 in words is "eighteen million, one hundred thirty-nine thousand, two hundred twenty-nine".