2001820 has 24 divisors (see below), whose sum is σ = 4249728. Its totient is φ = 792000.

The previous prime is 2001809. The next prime is 2001833. The reversal of 2001820 is 281002.

It is a self number, because there is not a number n which added to its sum of digits gives 2001820.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1525 + ... + 2515.

It is an arithmetic number, because the mean of its divisors is an integer number (177072).

2^2001820 is an apocalyptic number.

2001820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2001820 is an abundant number, since it is smaller than the sum of its proper divisors (2247908).

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

2001820 is a wasteful number, since it uses less digits than its factorization.

2001820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1101 (or 1099 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 2001820 is about 1414.8568832218. The cubic root of 2001820 is about 126.0303110079.

Adding to 2001820 its reverse (281002), we get a palindrome (2282822).

The spelling of 2001820 in words is "two million, one thousand, eight hundred twenty".