809109797 has 2 divisors, whose sum is σ = 809109798. Its totient is φ = 809109796.

The previous prime is 809109787. The next prime is 809109799. The reversal of 809109797 is 797901908.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 425968321 + 383141476 = 20639^2 + 19574^2 .

It is a cyclic number.

It is not a de Polignac number, because 809109797 - 2⁶ = 809109733 is a prime.

Together with 809109799, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (809109799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 404554898 + 404554899.

It is an arithmetic number, because the mean of its divisors is an integer number (404554899).

Almost surely, 2^809109797 is an apocalyptic number.

It is an amenable number.

809109797 is a deficient number, since it is larger than the sum of its proper divisors (1).

809109797 is an equidigital number, since it uses as much as digits as its factorization.

809109797 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 285768, while the sum is 50.

The square root of 809109797 is about 28444.8553696446. The cubic root of 809109797 is about 931.8281367695.

The spelling of 809109797 in words is "eight hundred nine million, one hundred nine thousand, seven hundred ninety-seven".