812643457 has 4 divisors (see below), whose sum is σ = 812942676. Its totient is φ = 812344240.

The previous prime is 812643451. The next prime is 812643473. The reversal of 812643457 is 754346218.

812643457 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 can be written as a sum of positive squares in 2 ways, for example, as 288966001 + 523677456 = 16999^2 + 22884^2 .

It is a cyclic number.

It is not a de Polignac number, because 812643457 - 2³ = 812643449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (812643451) 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, 145498 + ... + 150979.

It is an arithmetic number, because the mean of its divisors is an integer number (203235669).

Almost surely, 2^812643457 is an apocalyptic number.

It is an amenable number.

812643457 is a deficient number, since it is larger than the sum of its proper divisors (299219).

812643457 is a wasteful number, since it uses less digits than its factorization.

812643457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299218.

The product of its digits is 161280, while the sum is 40.

The square root of 812643457 is about 28506.9019186582. The cubic root of 812643457 is about 933.1827044189.

The spelling of 812643457 in words is "eight hundred twelve million, six hundred forty-three thousand, four hundred fifty-seven".