812840 has 32 divisors (see below), whose sum is σ = 2090880. Its totient is φ = 278592.

The previous prime is 812807. The next prime is 812849. The reversal of 812840 is 48218.

It is not an unprimeable number, because it can be changed into a prime (812849) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1172 + ... + 1731.

It is an arithmetic number, because the mean of its divisors is an integer number (65340).

2⁸¹²⁸⁴⁰ is an apocalyptic number.

It is an amenable number.

812840 is an abundant number, since it is smaller than the sum of its proper divisors (1278040).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

812840 is a wasteful number, since it uses less digits than its factorization.

812840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2921 (or 2917 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 23.

The square root of 812840 is about 901.5763972066. The cubic root of 812840 is about 93.3257930416.

The spelling of 812840 in words is "eight hundred twelve thousand, eight hundred forty".