221224 has 8 divisors (see below), whose sum is σ = 414810. Its totient is φ = 110608.

The previous prime is 221219. The next prime is 221227. The reversal of 221224 is 422122.

It can be written as a sum of positive squares in only one way, i.e., 220900 + 324 = 470^2 + 18^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (221227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13819 + ... + 13834.

2²²¹²²⁴ is an apocalyptic number.

It is an amenable number.

221224 is a deficient number, since it is larger than the sum of its proper divisors (193586).

221224 is a wasteful number, since it uses less digits than its factorization.

221224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27659 (or 27655 counting only the distinct ones).

The product of its digits is 64, while the sum is 13.

The square root of 221224 is about 470.3445545555. The cubic root of 221224 is about 60.4798557801.

Adding to 221224 its reverse (422122), we get a palindrome (643346).

It can be divided in two parts, 22122 and 4, that multiplied together give a palindrome (88488).

The spelling of 221224 in words is "two hundred twenty-one thousand, two hundred twenty-four", and thus it is an iban number.