816905809984 has 56 divisors (see below), whose sum is σ = 1768765287456. Its totient is φ = 371247360000.

The previous prime is 816905809981. The next prime is 816905810023. The reversal of 816905809984 is 489908509618.

It is a super-2 number, since 2×816905809984² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (816905809981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3528184 + ... + 3752584.

Almost surely, 2^816905809984 is an apocalyptic number.

It is an amenable number.

816905809984 is an abundant number, since it is smaller than the sum of its proper divisors (951859477472).

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

816905809984 is a wasteful number, since it uses less digits than its factorization.

816905809984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229595 (or 229585 counting only the distinct ones).

The product of its (nonzero) digits is 44789760, while the sum is 67.

The spelling of 816905809984 in words is "eight hundred sixteen billion, nine hundred five million, eight hundred nine thousand, nine hundred eighty-four".