2258821 has 2 divisors, whose sum is σ = 2258822. Its totient is φ = 2258820.

The previous prime is 2258819. The next prime is 2258827. The reversal of 2258821 is 1288522.

2258821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2208196 + 50625 = 1486^2 + 225^2 .

It is a cyclic number.

It is not a de Polignac number, because 2258821 - 2¹ = 2258819 is a prime.

Together with 2258819, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 2258821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2258827) 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 as a sum of consecutive naturals, namely, 1129410 + 1129411.

It is an arithmetic number, because the mean of its divisors is an integer number (1129411).

2^2258821 is an apocalyptic number.

It is an amenable number.

2258821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2258821 is an equidigital number, since it uses as much as digits as its factorization.

2258821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2560, while the sum is 28.

The square root of 2258821 is about 1502.9374571152. The cubic root of 2258821 is about 131.2080876000.

Subtracting from 2258821 its reverse (1288522), we obtain a cube (970299 = 99³).

The spelling of 2258821 in words is "two million, two hundred fifty-eight thousand, eight hundred twenty-one".