871902809 has 2 divisors, whose sum is σ = 871902810. Its totient is φ = 871902808.

The previous prime is 871902769. The next prime is 871902827. The reversal of 871902809 is 908209178.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 871902784 + 25 = 29528^2 + 5^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-871902809 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 871902809.

It is not a weakly prime, because it can be changed into another prime (871902859) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 435951404 + 435951405.

It is an arithmetic number, because the mean of its divisors is an integer number (435951405).

Almost surely, 2^871902809 is an apocalyptic number.

It is an amenable number.

871902809 is a deficient number, since it is larger than the sum of its proper divisors (1).

871902809 is an equidigital number, since it uses as much as digits as its factorization.

871902809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72576, while the sum is 44.

The square root of 871902809 is about 29528.0004233270. Note that the first 3 decimals coincide. The cubic root of 871902809 is about 955.3357404364.

The spelling of 871902809 in words is "eight hundred seventy-one million, nine hundred two thousand, eight hundred nine".