18318437 has 2 divisors, whose sum is σ = 18318438. Its totient is φ = 18318436.

The previous prime is 18318389. The next prime is 18318449. The reversal of 18318437 is 73481381.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10201636 + 8116801 = 3194^2 + 2849^2 .

It is an emirp because it is prime and its reverse (73481381) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18318437 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 18318397 and 18318406.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18318457) 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, 9159218 + 9159219.

It is an arithmetic number, because the mean of its divisors is an integer number (9159219).

Almost surely, 2^18318437 is an apocalyptic number.

It is an amenable number.

18318437 is a deficient number, since it is larger than the sum of its proper divisors (1).

18318437 is an equidigital number, since it uses as much as digits as its factorization.

18318437 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16128, while the sum is 35.

The square root of 18318437 is about 4280.0043224277. The cubic root of 18318437 is about 263.6105608264.

The spelling of 18318437 in words is "eighteen million, three hundred eighteen thousand, four hundred thirty-seven".