82021800 has 192 divisors, whose sum is σ = 296409600. Its totient is φ = 18374400.

The previous prime is 82021789. The next prime is 82021801. The reversal of 82021800 is 812028.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82021801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 247635 + ... + 247965.

It is an arithmetic number, because the mean of its divisors is an integer number (1543800).

Almost surely, 2^82021800 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 82021800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (148204800).

82021800 is an abundant number, since it is smaller than the sum of its proper divisors (214387800).

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

82021800 is a wasteful number, since it uses less digits than its factorization.

82021800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 416 (or 407 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 21.

The square root of 82021800 is about 9056.5887617800. The cubic root of 82021800 is about 434.4866450422.

Adding to 82021800 its reverse (812028), we get a palindrome (82833828).

The spelling of 82021800 in words is "eighty-two million, twenty-one thousand, eight hundred".