812005 has 16 divisors (see below), whose sum is σ = 1061424. Its totient is φ = 593920.

The previous prime is 811997. The next prime is 812011. The reversal of 812005 is 500218.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 103041 + 708964 = 321^2 + 842^2 .

It is not a de Polignac number, because 812005 - 2³ = 811997 is a prime.

It is a Duffinian number.

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 812005.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3369 + ... + 3601.

It is an arithmetic number, because the mean of its divisors is an integer number (66339).

2⁸¹²⁰⁰⁵ is an apocalyptic number.

812005 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

812005 is a deficient number, since it is larger than the sum of its proper divisors (249419).

812005 is a wasteful number, since it uses less digits than its factorization.

812005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 296.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 812005 is about 901.1132004360. The cubic root of 812005 is about 93.2938253989.

The spelling of 812005 in words is "eight hundred twelve thousand, five".