821102400 has 336 divisors, whose sum is σ = 3042513600. Its totient is φ = 215377920.

The previous prime is 821102377. The next prime is 821102413. The reversal of 821102400 is 4201128.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3585486 + ... + 3585714.

It is an arithmetic number, because the mean of its divisors is an integer number (9055100).

Almost surely, 2^821102400 is an apocalyptic number.

821102400 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 821102400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1521256800).

821102400 is an abundant number, since it is smaller than the sum of its proper divisors (2221411200).

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

821102400 is a wasteful number, since it uses less digits than its factorization.

821102400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343 (or 322 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 821102400 is about 28654.8844003950. The cubic root of 821102400 is about 936.4094198358.

Adding to 821102400 its reverse (4201128), we get a palindrome (825303528).

The spelling of 821102400 in words is "eight hundred twenty-one million, one hundred two thousand, four hundred".