820540 has 24 divisors (see below), whose sum is σ = 1969632. Its totient is φ = 281280.

The previous prime is 820537. The next prime is 820541. The reversal of 820540 is 45028.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2791 + ... + 3070.

It is an arithmetic number, because the mean of its divisors is an integer number (82068).

2⁸²⁰⁵⁴⁰ is an apocalyptic number.

It is an amenable number.

820540 is an abundant number, since it is smaller than the sum of its proper divisors (1149092).

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

820540 is a wasteful number, since it uses less digits than its factorization.

820540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5877 (or 5875 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 820540 is about 905.8366298621. The cubic root of 820540 is about 93.6195578484.

Adding to 820540 its reverse (45028), we get a palindrome (865568).

The spelling of 820540 in words is "eight hundred twenty thousand, five hundred forty".