2228821 has 4 divisors (see below), whose sum is σ = 2547232. Its totient is φ = 1910412.

The previous prime is 2228813. The next prime is 2228867. The reversal of 2228821 is 1288222.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 2228821 - 2³ = 2228813 is a prime.

It is a d-powerful number, because it can be written as 2² + 2⁴ + 2¹⁷ + 8² + 8³ + 2²¹ + 1 .

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2228221) 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 3 ways as a sum of consecutive naturals, for example, 159195 + ... + 159208.

It is an arithmetic number, because the mean of its divisors is an integer number (636808).

2^2228821 is an apocalyptic number.

It is an amenable number.

2228821 is a deficient number, since it is larger than the sum of its proper divisors (318411).

2228821 is an equidigital number, since it uses as much as digits as its factorization.

2228821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318410.

The product of its digits is 1024, while the sum is 25.

The square root of 2228821 is about 1492.9236417178. The cubic root of 2228821 is about 130.6246271061.

The spelling of 2228821 in words is "two million, two hundred twenty-eight thousand, eight hundred twenty-one".