290820 has 48 divisors (see below), whose sum is σ = 842688. Its totient is φ = 74880.

The previous prime is 290803. The next prime is 290821. The reversal of 290820 is 28092.

It is not an unprimeable number, because it can be changed into a prime (290821) by changing a digit.

290820 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 (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2155 + ... + 2285.

It is an arithmetic number, because the mean of its divisors is an integer number (17556).

2²⁹⁰⁸²⁰ is an apocalyptic number.

290820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 290820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (421344).

290820 is an abundant number, since it is smaller than the sum of its proper divisors (551868).

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

290820 is a wasteful number, since it uses less digits than its factorization.

290820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180 (or 178 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 290820 is about 539.2772941632. The cubic root of 290820 is about 66.2533877465.

The spelling of 290820 in words is "two hundred ninety thousand, eight hundred twenty".