821998800 has 480 divisors, whose sum is σ = 3409781760. Its totient is φ = 184204800.

The previous prime is 821998799. The next prime is 821998811. The reversal of 821998800 is 8899128.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 6274735 + ... + 6274865.

It is an arithmetic number, because the mean of its divisors is an integer number (7103712).

Almost surely, 2^821998800 is an apocalyptic number.

821998800 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 821998800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1704890880).

821998800 is an abundant number, since it is smaller than the sum of its proper divisors (2587782960).

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

821998800 is a wasteful number, since it uses less digits than its factorization.

821998800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248 (or 231 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 45.

The square root of 821998800 is about 28670.5214462521. The cubic root of 821998800 is about 936.7500562500.

The spelling of 821998800 in words is "eight hundred twenty-one million, nine hundred ninety-eight thousand, eight hundred".