820100 has 36 divisors (see below), whose sum is σ = 1822800. Its totient is φ = 320160.

The previous prime is 820093. The next prime is 820109. The reversal of 820100 is 1028.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 820100.

It is not an unprimeable number, because it can be changed into a prime (820109) by changing a digit.

820100 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5831 + ... + 5969.

2⁸²⁰¹⁰⁰ 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 820100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (911400).

820100 is an abundant number, since it is smaller than the sum of its proper divisors (1002700).

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

820100 is a wasteful number, since it uses less digits than its factorization.

820100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212 (or 205 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 820100 is about 905.5937278935. The cubic root of 820100 is about 93.6028209148.

Adding to 820100 its reverse (1028), we get a palindrome (821128).

The spelling of 820100 in words is "eight hundred twenty thousand, one hundred".