820530 has 40 divisors (see below), whose sum is σ = 2208492. Its totient is φ = 218592.

The previous prime is 820489. The next prime is 820537. The reversal of 820530 is 35028.

It can be written as a sum of positive squares in 2 ways, for example, as 670761 + 149769 = 819^2 + 387^2 .

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

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (820537) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 304 + ... + 1316.

2⁸²⁰⁵³⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 820530, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1104246).

820530 is an abundant number, since it is smaller than the sum of its proper divisors (1387962).

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

820530 is a wasteful number, since it uses less digits than its factorization.

820530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1032 (or 1023 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 820530 is about 905.8311100862. The cubic root of 820530 is about 93.6191775300.

Adding to 820530 its reverse (35028), we get a palindrome (855558).

The spelling of 820530 in words is "eight hundred twenty thousand, five hundred thirty".