820900 has 18 divisors (see below), whose sum is σ = 1781570. Its totient is φ = 328320.

The previous prime is 820891. The next prime is 820901. The reversal of 820900 is 9028.

It can be written as a sum of positive squares in 3 ways, for example, as 64 + 820836 = 8^2 + 906^2 .

It is an Ulam number.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (820901) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4005 + ... + 4204.

2⁸²⁰⁹⁰⁰ is an apocalyptic number.

It is an amenable number.

820900 is an abundant number, since it is smaller than the sum of its proper divisors (960670).

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

820900 is a wasteful number, since it uses less digits than its factorization.

820900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8223 (or 8216 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 820900 is about 906.0353193999. The cubic root of 820900 is about 93.6332472534.

Adding to 820900 its reverse (9028), we get a palindrome (829928).

The spelling of 820900 in words is "eight hundred twenty thousand, nine hundred".