18500351917 has 2 divisors, whose sum is σ = 18500351918. Its totient is φ = 18500351916.

The previous prime is 18500351911. The next prime is 18500351929. The reversal of 18500351917 is 71915300581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17185636836 + 1314715081 = 131094^2 + 36259^2 .

It is a cyclic number.

It is not a de Polignac number, because 18500351917 - 2⁷ = 18500351789 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 18500351917.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18500351911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9250175958 + 9250175959.

It is an arithmetic number, because the mean of its divisors is an integer number (9250175959).

Almost surely, 2^18500351917 is an apocalyptic number.

It is an amenable number.

18500351917 is a deficient number, since it is larger than the sum of its proper divisors (1).

18500351917 is an equidigital number, since it uses as much as digits as its factorization.

18500351917 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 37800, while the sum is 40.

The spelling of 18500351917 in words is "eighteen billion, five hundred million, three hundred fifty-one thousand, nine hundred seventeen".