28221304 has 8 divisors (see below), whose sum is σ = 52914960. Its totient is φ = 14110648.

The previous prime is 28221283. The next prime is 28221311. The reversal of 28221304 is 40312282.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1763824 + ... + 1763839.

It is an arithmetic number, because the mean of its divisors is an integer number (6614370).

Almost surely, 2^28221304 is an apocalyptic number.

It is an amenable number.

28221304 is a deficient number, since it is larger than the sum of its proper divisors (24693656).

28221304 is a wasteful number, since it uses less digits than its factorization.

28221304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3527669 (or 3527665 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 28221304 is about 5312.3727278872. The cubic root of 28221304 is about 304.4568097621.

Adding to 28221304 its reverse (40312282), we get a palindrome (68533586).

The spelling of 28221304 in words is "twenty-eight million, two hundred twenty-one thousand, three hundred four".