805318681 has 2 divisors, whose sum is σ = 805318682. Its totient is φ = 805318680.

The previous prime is 805318649. The next prime is 805318687. The reversal of 805318681 is 186813508.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 429152656 + 376166025 = 20716^2 + 19395^2 .

It is a cyclic number.

It is not a de Polignac number, because 805318681 - 2⁵ = 805318649 is a prime.

It is a super-2 number, since 2×805318681² = 1297076355935159522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (805318687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 402659340 + 402659341.

It is an arithmetic number, because the mean of its divisors is an integer number (402659341).

Almost surely, 2^805318681 is an apocalyptic number.

It is an amenable number.

805318681 is a deficient number, since it is larger than the sum of its proper divisors (1).

805318681 is an equidigital number, since it uses as much as digits as its factorization.

805318681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 46080, while the sum is 40.

The square root of 805318681 is about 28378.1373772135. The cubic root of 805318681 is about 930.3704852182.

The spelling of 805318681 in words is "eight hundred five million, three hundred eighteen thousand, six hundred eighty-one".