2218821 has 16 divisors (see below), whose sum is σ = 3276288. Its totient is φ = 1324400.

The previous prime is 2218807. The next prime is 2218831. The reversal of 2218821 is 1288122.

2218821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2218821 - 2¹⁴ = 2202437 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2218791 and 2218800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2218831) 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 15 ways as a sum of consecutive naturals, for example, 1870 + ... + 2816.

It is an arithmetic number, because the mean of its divisors is an integer number (204768).

2^2218821 is an apocalyptic number.

It is an amenable number.

2218821 is a deficient number, since it is larger than the sum of its proper divisors (1057467).

2218821 is a wasteful number, since it uses less digits than its factorization.

2218821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1032.

The product of its digits is 512, while the sum is 24.

The square root of 2218821 is about 1489.5707435365. The cubic root of 2218821 is about 130.4289773697.

The spelling of 2218821 in words is "two million, two hundred eighteen thousand, eight hundred twenty-one".