812267509 has 4 divisors (see below), whose sum is σ = 812345004. Its totient is φ = 812190016.

The previous prime is 812267501. The next prime is 812267513. The reversal of 812267509 is 905762218.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 248062500 + 564205009 = 15750^2 + 23753^2 .

It is a cyclic number.

It is not a de Polignac number, because 812267509 - 2³ = 812267501 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 (812267501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20002 + ... + 44995.

It is an arithmetic number, because the mean of its divisors is an integer number (203086251).

Almost surely, 2^812267509 is an apocalyptic number.

It is an amenable number.

812267509 is a deficient number, since it is larger than the sum of its proper divisors (77495).

812267509 is a wasteful number, since it uses less digits than its factorization.

812267509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77494.

The product of its (nonzero) digits is 60480, while the sum is 40.

The square root of 812267509 is about 28500.3071737832. The cubic root of 812267509 is about 933.0387781239.

The spelling of 812267509 in words is "eight hundred twelve million, two hundred sixty-seven thousand, five hundred nine".