809056217 has 2 divisors, whose sum is σ = 809056218. Its totient is φ = 809056216.

The previous prime is 809056189. The next prime is 809056229. The reversal of 809056217 is 712650908.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 671017216 + 138039001 = 25904^2 + 11749^2 .

It is a cyclic number.

It is not a de Polignac number, because 809056217 - 2¹⁰ = 809055193 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (809056247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 404528108 + 404528109.

It is an arithmetic number, because the mean of its divisors is an integer number (404528109).

Almost surely, 2^809056217 is an apocalyptic number.

It is an amenable number.

809056217 is a deficient number, since it is larger than the sum of its proper divisors (1).

809056217 is an equidigital number, since it uses as much as digits as its factorization.

809056217 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 38.

The square root of 809056217 is about 28443.9135317206. The cubic root of 809056217 is about 931.8075674747.

The spelling of 809056217 in words is "eight hundred nine million, fifty-six thousand, two hundred seventeen".