812805709 has 4 divisors (see below), whose sum is σ = 839025280. Its totient is φ = 786586140.

The previous prime is 812805703. The next prime is 812805713. The reversal of 812805709 is 907508218.

812805709 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-812805709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (812805703) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13109739 + ... + 13109800.

It is an arithmetic number, because the mean of its divisors is an integer number (209756320).

Almost surely, 2^812805709 is an apocalyptic number.

It is an amenable number.

812805709 is a deficient number, since it is larger than the sum of its proper divisors (26219571).

812805709 is a wasteful number, since it uses less digits than its factorization.

812805709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26219570.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 812805709 is about 28509.7476137548. The cubic root of 812805709 is about 933.2448065553.

The spelling of 812805709 in words is "eight hundred twelve million, eight hundred five thousand, seven hundred nine".