816865812 has 36 divisors (see below), whose sum is σ = 2359835296. Its totient is φ = 233390160.

The previous prime is 816865811. The next prime is 816865849. The reversal of 816865812 is 218568618.

816865812 is a `hidden beast` number, since 8 + 1 + 68 + 6 + 581 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816865811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1620514 + ... + 1621017.

Almost surely, 2^816865812 is an apocalyptic number.

It is an amenable number.

816865812 is an abundant number, since it is smaller than the sum of its proper divisors (1542969484).

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

816865812 is a wasteful number, since it uses less digits than its factorization.

816865812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3241548 (or 3241543 counting only the distinct ones).

The product of its digits is 184320, while the sum is 45.

The square root of 816865812 is about 28580.8644375918. The cubic root of 816865812 is about 934.7961319746.

The spelling of 816865812 in words is "eight hundred sixteen million, eight hundred sixty-five thousand, eight hundred twelve".