2081820 has 96 divisors (see below), whose sum is σ = 6689088. Its totient is φ = 479232.

The previous prime is 2081813. The next prime is 2081831. The reversal of 2081820 is 281802.

2081820 is a nontrivial binomial coefficient, being equal to C(2041, 2).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13182 + ... + 13338.

It is an arithmetic number, because the mean of its divisors is an integer number (69678).

2^2081820 is an apocalyptic number.

2081820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

2081820 is the 2040-th triangular number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2081820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3344544).

2081820 is an abundant number, since it is smaller than the sum of its proper divisors (4607268).

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

2081820 is a wasteful number, since it uses less digits than its factorization.

2081820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199 (or 197 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 21.

The square root of 2081820 is about 1442.8513436941. The cubic root of 2081820 is about 127.6873063984.

The spelling of 2081820 in words is "two million, eighty-one thousand, eight hundred twenty".