2123221 has 4 divisors (see below), whose sum is σ = 2191744. Its totient is φ = 2054700.

The previous prime is 2123213. The next prime is 2123237. The reversal of 2123221 is 1223212.

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 not a de Polignac number, because 2123221 - 2³ = 2123213 is a prime.

It is a d-powerful number, because it can be written as 2⁹ + 1 + 2¹² + 3¹³ + 2¹⁸ + 2¹⁸ + 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 (2123281) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34215 + ... + 34276.

It is an arithmetic number, because the mean of its divisors is an integer number (547936).

2^2123221 is an apocalyptic number.

It is an amenable number.

2123221 is a deficient number, since it is larger than the sum of its proper divisors (68523).

2123221 is an equidigital number, since it uses as much as digits as its factorization.

2123221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68522.

The product of its digits is 48, while the sum is 13.

The square root of 2123221 is about 1457.1276539823. The cubic root of 2123221 is about 128.5281925757.

Adding to 2123221 its reverse (1223212), we get a palindrome (3346433).

Subtracting from 2123221 its reverse (1223212), we obtain a palindrome (900009).

The spelling of 2123221 in words is "two million, one hundred twenty-three thousand, two hundred twenty-one".