818784675809 has 2 divisors, whose sum is σ = 818784675810. Its totient is φ = 818784675808.

The previous prime is 818784675799. The next prime is 818784675811. The reversal of 818784675809 is 908576487818.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 807667082209 + 11117593600 = 898703^2 + 105440^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-818784675809 is a prime.

It is a Sophie Germain prime.

Together with 818784675811, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (818784675829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409392337904 + 409392337905.

It is an arithmetic number, because the mean of its divisors is an integer number (409392337905).

Almost surely, 2^818784675809 is an apocalyptic number.

It is an amenable number.

818784675809 is a deficient number, since it is larger than the sum of its proper divisors (1).

818784675809 is an equidigital number, since it uses as much as digits as its factorization.

818784675809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216760320, while the sum is 71.

The spelling of 818784675809 in words is "eight hundred eighteen billion, seven hundred eighty-four million, six hundred seventy-five thousand, eight hundred nine".