18509449037 has 2 divisors, whose sum is σ = 18509449038. Its totient is φ = 18509449036.

The previous prime is 18509449009. The next prime is 18509449061. The reversal of 18509449037 is 73094490581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18378140356 + 131308681 = 135566^2 + 11459^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18509449037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18509449087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9254724518 + 9254724519.

It is an arithmetic number, because the mean of its divisors is an integer number (9254724519).

Almost surely, 2^18509449037 is an apocalyptic number.

It is an amenable number.

18509449037 is a deficient number, since it is larger than the sum of its proper divisors (1).

18509449037 is an equidigital number, since it uses as much as digits as its factorization.

18509449037 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1088640, while the sum is 50.

The spelling of 18509449037 in words is "eighteen billion, five hundred nine million, four hundred forty-nine thousand, thirty-seven".