812391636 has 48 divisors (see below), whose sum is σ = 2168732160. Its totient is φ = 231859680.

The previous prime is 812391623. The next prime is 812391659. The reversal of 812391636 is 636193218.

It is a junction number, because it is equal to n+sod(n) for n = 812391594 and 812391603.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 80851 + ... + 90341.

It is an arithmetic number, because the mean of its divisors is an integer number (45181920).

Almost surely, 2^812391636 is an apocalyptic number.

It is an amenable number.

812391636 is an abundant number, since it is smaller than the sum of its proper divisors (1356340524).

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

812391636 is a wasteful number, since it uses less digits than its factorization.

812391636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10524 (or 10522 counting only the distinct ones).

The product of its digits is 46656, while the sum is 39.

The square root of 812391636 is about 28502.4847337912. The cubic root of 812391636 is about 933.0863032739.

The spelling of 812391636 in words is "eight hundred twelve million, three hundred ninety-one thousand, six hundred thirty-six".