42820 has 12 divisors (see below), whose sum is σ = 89964. Its totient is φ = 17120.

The previous prime is 42797. The next prime is 42821. The reversal of 42820 is 2824.

42820 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 30276 + 12544 = 174^2 + 112^2 .

It is an Ulam number.

42820 is strictly pandigital in base 6.

It is a nialpdrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 42794 and 42803.

It is not an unprimeable number, because it can be changed into a prime (42821) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 1051 + ... + 1090.

It is an arithmetic number, because the mean of its divisors is an integer number (7497).

2⁴²⁸²⁰ is an apocalyptic number.

It is an amenable number.

42820 is an abundant number, since it is smaller than the sum of its proper divisors (47144).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44982).

42820 is a wasteful number, since it uses less digits than its factorization.

42820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2150 (or 2148 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 42820 is about 206.9299398347. The cubic root of 42820 is about 34.9850276096.

The spelling of 42820 in words is "forty-two thousand, eight hundred twenty".