2259821 has 4 divisors (see below), whose sum is σ = 2263200. Its totient is φ = 2256444.

The previous prime is 2259811. The next prime is 2259823. The reversal of 2259821 is 1289522.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2259821 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2259823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 311 + ... + 2148.

It is an arithmetic number, because the mean of its divisors is an integer number (565800).

2^2259821 is an apocalyptic number.

It is an amenable number.

2259821 is a deficient number, since it is larger than the sum of its proper divisors (3379).

2259821 is an equidigital number, since it uses as much as digits as its factorization.

2259821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3378.

The product of its digits is 2880, while the sum is 29.

The square root of 2259821 is about 1503.2701021440. The cubic root of 2259821 is about 131.2274470697.

Subtracting from 2259821 its reverse (1289522), we obtain a cube (970299 = 99³).

The spelling of 2259821 in words is "two million, two hundred fifty-nine thousand, eight hundred twenty-one".