812821756 has 12 divisors (see below), whose sum is σ = 1443668968. Its totient is φ = 400344912.

The previous prime is 812821747. The next prime is 812821759. The reversal of 812821756 is 657128218.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (812821759) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1516191 + ... + 1516726.

Almost surely, 2^812821756 is an apocalyptic number.

It is an amenable number.

812821756 is a deficient number, since it is larger than the sum of its proper divisors (630847212).

812821756 is a wasteful number, since it uses less digits than its factorization.

812821756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3032988 (or 3032986 counting only the distinct ones).

The product of its digits is 53760, while the sum is 40.

The square root of 812821756 is about 28510.0290424265. The cubic root of 812821756 is about 933.2509481136.

It can be divided in two parts, 81282 and 1756, that added together give a palindrome (83038).

The spelling of 812821756 in words is "eight hundred twelve million, eight hundred twenty-one thousand, seven hundred fifty-six".