812813 has 4 divisors (see below), whose sum is σ = 820380. Its totient is φ = 805248.

The previous prime is 812807. The next prime is 812849. The reversal of 812813 is 318218.

812813 = 637² + 638².

812813 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 405769 + 407044 = 637^2 + 638^2 .

It is a cyclic number.

It is not a de Polignac number, because 812813 - 2¹⁶ = 747277 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 (812213) 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, 3620 + ... + 3837.

It is an arithmetic number, because the mean of its divisors is an integer number (205095).

2⁸¹²⁸¹³ is an apocalyptic number.

812813 is the 638-th centered square number.

It is an amenable number.

812813 is a deficient number, since it is larger than the sum of its proper divisors (7567).

812813 is a wasteful number, since it uses less digits than its factorization.

812813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7566.

The product of its digits is 384, while the sum is 23.

The square root of 812813 is about 901.5614233096. The cubic root of 812813 is about 93.3247597000.

It can be divided in two parts, 8 and 12813, that added together give a palindrome (12821).

The spelling of 812813 in words is "eight hundred twelve thousand, eight hundred thirteen".