2161220 has 12 divisors (see below), whose sum is σ = 4538604. Its totient is φ = 864480.

The previous prime is 2161213. The next prime is 2161253. The reversal of 2161220 is 221612.

2161220 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 1149184 + 1012036 = 1072^2 + 1006^2 .

It is a junction number, because it is equal to n+sod(n) for n = 2161195 and 2161204.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54011 + ... + 54050.

It is an arithmetic number, because the mean of its divisors is an integer number (378217).

2^2161220 is an apocalyptic number.

2161220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2161220 is an abundant number, since it is smaller than the sum of its proper divisors (2377384).

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

2161220 is a wasteful number, since it uses less digits than its factorization.

2161220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108070 (or 108068 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 2161220 is about 1470.1088395082. The cubic root of 2161220 is about 129.2904139540.

Adding to 2161220 its reverse (221612), we get a palindrome (2382832).

The spelling of 2161220 in words is "two million, one hundred sixty-one thousand, two hundred twenty".