809999999959 has 2 divisors, whose sum is σ = 809999999960. Its totient is φ = 809999999958.

The previous prime is 809999999947. The next prime is 810000000023. The reversal of 809999999959 is 959999999908.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-809999999959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (809999999059) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 404999999979 + 404999999980.

It is an arithmetic number, because the mean of its divisors is an integer number (404999999980).

Almost surely, 2^809999999959 is an apocalyptic number.

809999999959 is a deficient number, since it is larger than the sum of its proper divisors (1).

809999999959 is an equidigital number, since it uses as much as digits as its factorization.

809999999959 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15496819560, while the sum is 94.

The spelling of 809999999959 in words is "eight hundred nine billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred fifty-nine".