812523856 has 40 divisors (see below), whose sum is σ = 1631848680. Its totient is φ = 391458816.

The previous prime is 812523851. The next prime is 812523871. The reversal of 812523856 is 658325218.

It can be written as a sum of positive squares in 4 ways, for example, as 284259600 + 528264256 = 16860^2 + 22984^2 .

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (812523851) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 273676 + ... + 276628.

It is an arithmetic number, because the mean of its divisors is an integer number (40796217).

Almost surely, 2^812523856 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 812523856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (815924340).

812523856 is an abundant number, since it is smaller than the sum of its proper divisors (819324824).

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

812523856 is a wasteful number, since it uses less digits than its factorization.

812523856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3583 (or 3577 counting only the distinct ones).

The product of its digits is 115200, while the sum is 40.

The square root of 812523856 is about 28504.8040863290. The cubic root of 812523856 is about 933.1369217084.

The spelling of 812523856 in words is "eight hundred twelve million, five hundred twenty-three thousand, eight hundred fifty-six".