23031221 has 4 divisors (see below), whose sum is σ = 23408844. Its totient is φ = 22653600.

The previous prime is 23031167. The next prime is 23031227. The reversal of 23031221 is 12213032.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6180196 + 16851025 = 2486^2 + 4105^2 .

It is a cyclic number.

It is not a de Polignac number, because 23031221 - 2⁶ = 23031157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 23031196 and 23031205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23031227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 188720 + ... + 188841.

It is an arithmetic number, because the mean of its divisors is an integer number (5852211).

Almost surely, 2^23031221 is an apocalyptic number.

It is an amenable number.

23031221 is a deficient number, since it is larger than the sum of its proper divisors (377623).

23031221 is an equidigital number, since it uses as much as digits as its factorization.

23031221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 377622.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 23031221 is about 4799.0854337051. The cubic root of 23031221 is about 284.5153186032.

Adding to 23031221 its reverse (12213032), we get a palindrome (35244253).

The spelling of 23031221 in words is "twenty-three million, thirty-one thousand, two hundred twenty-one".