2100820 has 24 divisors (see below), whose sum is σ = 4604544. Its totient is φ = 803616.

The previous prime is 2100803. The next prime is 2100821. The reversal of 2100820 is 280012.

It is a self number, because there is not a number n which added to its sum of digits gives 2100820.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100821) 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 7 ways as a sum of consecutive naturals, for example, 1824 + ... + 2743.

It is an arithmetic number, because the mean of its divisors is an integer number (191856).

2^2100820 is an apocalyptic number.

2100820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2100820 is an abundant number, since it is smaller than the sum of its proper divisors (2503724).

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

2100820 is a wasteful number, since it uses less digits than its factorization.

2100820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4599 (or 4597 counting only the distinct ones).

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

The square root of 2100820 is about 1449.4205738846. The cubic root of 2100820 is about 128.0745821856.

Adding to 2100820 its reverse (280012), we get a palindrome (2380832).

The spelling of 2100820 in words is "two million, one hundred thousand, eight hundred twenty".