808740809 has 2 divisors, whose sum is σ = 808740810. Its totient is φ = 808740808.

The previous prime is 808740791. The next prime is 808740817. The reversal of 808740809 is 908047808.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 409860025 + 398880784 = 20245^2 + 19972^2 .

It is a cyclic number.

It is not a de Polignac number, because 808740809 - 2²⁴ = 791963593 is a prime.

It is a super-2 number, since 2×808740809² = 1308123392283948962, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 808740809.

It is not a weakly prime, because it can be changed into another prime (808740839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 404370404 + 404370405.

It is an arithmetic number, because the mean of its divisors is an integer number (404370405).

Almost surely, 2^808740809 is an apocalyptic number.

It is an amenable number.

808740809 is a deficient number, since it is larger than the sum of its proper divisors (1).

808740809 is an equidigital number, since it uses as much as digits as its factorization.

808740809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 129024, while the sum is 44.

The square root of 808740809 is about 28438.3686065147. The cubic root of 808740809 is about 931.6864643279.

The spelling of 808740809 in words is "eight hundred eight million, seven hundred forty thousand, eight hundred nine".