812420856 has 144 divisors (see below), whose sum is σ = 2402314200. Its totient is φ = 247912704.

The previous prime is 812420839. The next prime is 812420857. The reversal of 812420856 is 658024218.

812420856 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 812420856.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (812420857) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2177886 + ... + 2178258.

Almost surely, 2^812420856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 812420856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1201157100).

812420856 is an abundant number, since it is smaller than the sum of its proper divisors (1589893344).

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

812420856 is a wasteful number, since it uses less digits than its factorization.

812420856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 590 (or 570 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The square root of 812420856 is about 28502.9973160719. The cubic root of 812420856 is about 933.0974901833.

The spelling of 812420856 in words is "eight hundred twelve million, four hundred twenty thousand, eight hundred fifty-six".