999816800 has 72 divisors (see below), whose sum is σ = 2446999632. Its totient is φ = 398912000.

The previous prime is 999816799. The next prime is 999816871. The reversal of 999816800 is 8618999.

It is a Harshad number since it is a multiple of its sum of digits (50).

It is a congruent number.

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 11 ways as a sum of consecutive naturals, for example, 367445 + ... + 370155.

It is an arithmetic number, because the mean of its divisors is an integer number (33986106).

Almost surely, 2^999816800 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 999816800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1223499816).

999816800 is an abundant number, since it is smaller than the sum of its proper divisors (1447182832).

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

999816800 is a wasteful number, since it uses less digits than its factorization.

999816800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3192 (or 3179 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 50.

The square root of 999816800 is about 31619.8798226685. The cubic root of 999816800 is about 999.9389296038.

The spelling of 999816800 in words is "nine hundred ninety-nine million, eight hundred sixteen thousand, eight hundred".