221304436 has 24 divisors (see below), whose sum is σ = 427896000. Its totient is φ = 99614592.

The previous prime is 221304403. The next prime is 221304439. The reversal of 221304436 is 634403122.

221304436 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 221304436.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221304439) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69186 + ... + 72313.

It is an arithmetic number, because the mean of its divisors is an integer number (17829000).

Almost surely, 2^221304436 is an apocalyptic number.

It is an amenable number.

221304436 is a deficient number, since it is larger than the sum of its proper divisors (206591564).

221304436 is a wasteful number, since it uses less digits than its factorization.

221304436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141543 (or 141541 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 221304436 is about 14876.3045142266. The cubic root of 221304436 is about 604.8718495505.

Adding to 221304436 its reverse (634403122), we get a palindrome (855707558).

The spelling of 221304436 in words is "two hundred twenty-one million, three hundred four thousand, four hundred thirty-six".