812045 has 18 divisors (see below), whose sum is σ = 1090314. Its totient is φ = 580320.

The previous prime is 812033. The next prime is 812047. The reversal of 812045 is 540218.

It can be written as a sum of positive squares in 3 ways, for example, as 3844 + 808201 = 62^2 + 899^2 .

It is not a de Polignac number, because 812045 - 2⁶ = 811981 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (812047) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 26180 + ... + 26210.

It is an arithmetic number, because the mean of its divisors is an integer number (60573).

2⁸¹²⁰⁴⁵ is an apocalyptic number.

It is an amenable number.

812045 is a deficient number, since it is larger than the sum of its proper divisors (278269).

812045 is a wasteful number, since it uses less digits than its factorization.

812045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93 (or 49 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 812045 is about 901.1353949324. The cubic root of 812045 is about 93.2953572826.

Multiplying 812045 by its sum of digits (20), we get a square (16240900 = 4030²).

Multiplying 812045 by its product of nonzero digits (320), we get a square (259854400 = 16120²).

The spelling of 812045 in words is "eight hundred twelve thousand, forty-five".