223131221 has 4 divisors (see below), whose sum is σ = 223166412. Its totient is φ = 223096032.

The previous prime is 223131187. The next prime is 223131247. The reversal of 223131221 is 122131322.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 122131322 = 2 ⋅61065661.

It can be written as a sum of positive squares in 2 ways, for example, as 217887121 + 5244100 = 14761^2 + 2290^2 .

It is a cyclic number.

It is not a de Polignac number, because 223131221 - 2⁶ = 223131157 is a prime.

It is a super-3 number, since 3×223131221³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 223131221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (223131281) 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, 5150 + ... + 21743.

It is an arithmetic number, because the mean of its divisors is an integer number (55791603).

Almost surely, 2^223131221 is an apocalyptic number.

It is an amenable number.

223131221 is a deficient number, since it is larger than the sum of its proper divisors (35191).

223131221 is an equidigital number, since it uses as much as digits as its factorization.

223131221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35190.

The product of its digits is 144, while the sum is 17.

The square root of 223131221 is about 14937.5774809706. The cubic root of 223131221 is about 606.5316209423.

Adding to 223131221 its reverse (122131322), we get a palindrome (345262543).

The spelling of 223131221 in words is "two hundred twenty-three million, one hundred thirty-one thousand, two hundred twenty-one".