2101800 has 96 divisors (see below), whose sum is σ = 6785280. Its totient is φ = 537600.

The previous prime is 2101789. The next prime is 2101807. The reversal of 2101800 is 81012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (2101807) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 18544 + ... + 18656.

It is an arithmetic number, because the mean of its divisors is an integer number (70680).

2^2101800 is an apocalyptic number.

2101800 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 2101800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3392640).

2101800 is an abundant number, since it is smaller than the sum of its proper divisors (4683480).

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

2101800 is a wasteful number, since it uses less digits than its factorization.

2101800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163 (or 154 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 2101800 is about 1449.7586005953. The cubic root of 2101800 is about 128.0944940262.

Adding to 2101800 its reverse (81012), we get a palindrome (2182812).

The spelling of 2101800 in words is "two million, one hundred one thousand, eight hundred".