816856349805 has 192 divisors, whose sum is σ = 1494484992000. Its totient is φ = 412388121600.

The previous prime is 816856349753. The next prime is 816856349809. The reversal of 816856349805 is 508943658618.

816856349805 is a `hidden beast` number, since 8 + 1 + 6 + 85 + 63 + 498 + 0 + 5 = 666.

It is not a de Polignac number, because 816856349805 - 2⁹ = 816856349293 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816856349809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 3417808876 + ... + 3417809114.

It is an arithmetic number, because the mean of its divisors is an integer number (7783776000).

Almost surely, 2^816856349805 is an apocalyptic number.

It is an amenable number.

816856349805 is a deficient number, since it is larger than the sum of its proper divisors (677628642195).

816856349805 is a wasteful number, since it uses less digits than its factorization.

816856349805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 680 (or 677 counting only the distinct ones).

The product of its (nonzero) digits is 49766400, while the sum is 63.

The spelling of 816856349805 in words is "eight hundred sixteen billion, eight hundred fifty-six million, three hundred forty-nine thousand, eight hundred five".