18263931209 has 2 divisors, whose sum is σ = 18263931210. Its totient is φ = 18263931208.

The previous prime is 18263931197. The next prime is 18263931221. The reversal of 18263931209 is 90213936281.

It is a balanced prime because it is at equal distance from previous prime (18263931197) and next prime (18263931221).

It can be written as a sum of positive squares in only one way, i.e., 11995725625 + 6268205584 = 109525^2 + 79172^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18263931209 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 18263931209.

It is not a weakly prime, because it can be changed into another prime (18263931809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9131965604 + 9131965605.

It is an arithmetic number, because the mean of its divisors is an integer number (9131965605).

Almost surely, 2^18263931209 is an apocalyptic number.

It is an amenable number.

18263931209 is a deficient number, since it is larger than the sum of its proper divisors (1).

18263931209 is an equidigital number, since it uses as much as digits as its factorization.

18263931209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 139968, while the sum is 44.

The spelling of 18263931209 in words is "eighteen billion, two hundred sixty-three million, nine hundred thirty-one thousand, two hundred nine".