221221304 has 16 divisors (see below), whose sum is σ = 419067600. Its totient is φ = 109469952.

The previous prime is 221221249. The next prime is 221221327. The reversal of 221221304 is 403122122.

It is a congruent number.

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, 141764 + ... + 143315.

It is an arithmetic number, because the mean of its divisors is an integer number (26191725).

Almost surely, 2^221221304 is an apocalyptic number.

It is an amenable number.

221221304 is a deficient number, since it is larger than the sum of its proper divisors (197846296).

221221304 is a wasteful number, since it uses less digits than its factorization.

221221304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285182 (or 285178 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 221221304 is about 14873.5101438766. The cubic root of 221221304 is about 604.7961009495.

Adding to 221221304 its reverse (403122122), we get a palindrome (624343426).

The spelling of 221221304 in words is "two hundred twenty-one million, two hundred twenty-one thousand, three hundred four".