221121424 has 20 divisors (see below), whose sum is σ = 428837260. Its totient is φ = 110453760.

The previous prime is 221121413. The next prime is 221121443. The reversal of 221121424 is 424121122.

It can be written as a sum of positive squares in 2 ways, for example, as 35617024 + 185504400 = 5968^2 + 13620^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11944 + ... + 24184.

It is an arithmetic number, because the mean of its divisors is an integer number (21441863).

Almost surely, 2^221121424 is an apocalyptic number.

It is an amenable number.

221121424 is a deficient number, since it is larger than the sum of its proper divisors (207715836).

221121424 is a wasteful number, since it uses less digits than its factorization.

221121424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13378 (or 13372 counting only the distinct ones).

The product of its digits is 256, while the sum is 19.

The square root of 221121424 is about 14870.1521175810. The cubic root of 221121424 is about 604.7050667274.

Adding to 221121424 its reverse (424121122), we get a palindrome (645242546).

The spelling of 221121424 in words is "two hundred twenty-one million, one hundred twenty-one thousand, four hundred twenty-four".