816839920800 has 576 divisors, whose sum is σ = 2995008307200. Its totient is φ = 214839475200.

The previous prime is 816839920769. The next prime is 816839920879. The reversal of 816839920800 is 8029938618.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 523950421 + ... + 523951979.

It is an arithmetic number, because the mean of its divisors is an integer number (5199667200).

Almost surely, 2^816839920800 is an apocalyptic number.

816839920800 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 816839920800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1497504153600).

816839920800 is an abundant number, since it is smaller than the sum of its proper divisors (2178168386400).

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

816839920800 is a wasteful number, since it uses less digits than its factorization.

816839920800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1906 (or 1887 counting only the distinct ones).

The product of its (nonzero) digits is 1492992, while the sum is 54.

The spelling of 816839920800 in words is "eight hundred sixteen billion, eight hundred thirty-nine million, nine hundred twenty thousand, eight hundred".