2111820 has 48 divisors (see below), whose sum is σ = 6020448. Its totient is φ = 552960.

The previous prime is 2111819. The next prime is 2111839. The reversal of 2111820 is 281112.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 2111820.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3372 + ... + 3948.

It is an arithmetic number, because the mean of its divisors is an integer number (125426).

2^2111820 is an apocalyptic number.

2111820 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 2111820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3010224).

2111820 is an abundant number, since it is smaller than the sum of its proper divisors (3908628).

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

2111820 is a wasteful number, since it uses less digits than its factorization.

2111820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 650 (or 648 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

The square root of 2111820 is about 1453.2102394354. The cubic root of 2111820 is about 128.2977281709.

Adding to 2111820 its reverse (281112), we get a palindrome (2392932).

The spelling of 2111820 in words is "two million, one hundred eleven thousand, eight hundred twenty".