813285805 has 4 divisors (see below), whose sum is σ = 975942972. Its totient is φ = 650628640.

The previous prime is 813285793. The next prime is 813285817. The reversal of 813285805 is 508582318.

813285805 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (813285793) and next prime (813285817).

It can be written as a sum of positive squares in 2 ways, for example, as 509585476 + 303700329 = 22574^2 + 17427^2 .

It is a de Polignac number, because none of the positive numbers 2^k-813285805 is a prime.

It is a super-2 number, since 2×813285805² = 1322867601228996050, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81328576 + ... + 81328585.

It is an arithmetic number, because the mean of its divisors is an integer number (243985743).

Almost surely, 2^813285805 is an apocalyptic number.

It is an amenable number.

813285805 is a deficient number, since it is larger than the sum of its proper divisors (162657167).

813285805 is a wasteful number, since it uses less digits than its factorization.

813285805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162657166.

The product of its (nonzero) digits is 76800, while the sum is 40.

The square root of 813285805 is about 28518.1662278625. The cubic root of 813285805 is about 933.4285154488.

The spelling of 813285805 in words is "eight hundred thirteen million, two hundred eighty-five thousand, eight hundred five".