2156220 has 120 divisors (see below), whose sum is σ = 7440048. Its totient is φ = 522720.

The previous prime is 2156207. The next prime is 2156221. The reversal of 2156220 is 226512.

2156220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 2156193 and 2156202.

It is a Saint-Exupery number, since it is equal to the product of the sides of a Pythagorean triangle: 165 × 99 × 132.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2156221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 196015 + ... + 196025.

2^2156220 is an apocalyptic number.

2156220 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 2156220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3720024).

2156220 is an abundant number, since it is smaller than the sum of its proper divisors (5283828).

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

2156220 is a wasteful number, since it uses less digits than its factorization.

2156220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54 (or 21 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 2156220 is about 1468.4073004449. The cubic root of 2156220 is about 129.1906321586.

The spelling of 2156220 in words is "two million, one hundred fifty-six thousand, two hundred twenty".