805439813 has 2 divisors, whose sum is σ = 805439814. Its totient is φ = 805439812.

The previous prime is 805439807. The next prime is 805439827. The reversal of 805439813 is 318934508.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 519931204 + 285508609 = 22802^2 + 16897^2 .

It is a cyclic number.

It is not a de Polignac number, because 805439813 - 2⁴ = 805439797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (805439113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 402719906 + 402719907.

It is an arithmetic number, because the mean of its divisors is an integer number (402719907).

Almost surely, 2^805439813 is an apocalyptic number.

It is an amenable number.

805439813 is a deficient number, since it is larger than the sum of its proper divisors (1).

805439813 is an equidigital number, since it uses as much as digits as its factorization.

805439813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 103680, while the sum is 41.

The square root of 805439813 is about 28380.2715455649. The cubic root of 805439813 is about 930.4171301015.

The spelling of 805439813 in words is "eight hundred five million, four hundred thirty-nine thousand, eight hundred thirteen".