221424224 has 24 divisors (see below), whose sum is σ = 498205008. Its totient is φ = 94896000.

The previous prime is 221424223. The next prime is 221424241. The reversal of 221424224 is 422424122.

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

It is a self number, because there is not a number n which added to its sum of digits gives 221424224.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221424223) 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, 494027 + ... + 494474.

It is an arithmetic number, because the mean of its divisors is an integer number (20758542).

Almost surely, 2^221424224 is an apocalyptic number.

It is an amenable number.

221424224 is an abundant number, since it is smaller than the sum of its proper divisors (276780784).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221424224 is an equidigital number, since it uses as much as digits as its factorization.

221424224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 988518 (or 988510 counting only the distinct ones).

The product of its digits is 2048, while the sum is 23.

The square root of 221424224 is about 14880.3301038653. The cubic root of 221424224 is about 604.9809651821.

Adding to 221424224 its reverse (422424122), we get a palindrome (643848346).

The spelling of 221424224 in words is "two hundred twenty-one million, four hundred twenty-four thousand, two hundred twenty-four".