28597221 has 12 divisors (see below), whose sum is σ = 42640000. Its totient is φ = 18449640.

The previous prime is 28597207. The next prime is 28597237. The reversal of 28597221 is 12279582.

It is not a de Polignac number, because 28597221 - 2⁹ = 28596709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28597321) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 50971 + ... + 51528.

Almost surely, 2^28597221 is an apocalyptic number.

It is an amenable number.

28597221 is a deficient number, since it is larger than the sum of its proper divisors (14042779).

28597221 is a wasteful number, since it uses less digits than its factorization.

28597221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102536 (or 102533 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 28597221 is about 5347.6369547680. The cubic root of 28597221 is about 305.8026729842.

The spelling of 28597221 in words is "twenty-eight million, five hundred ninety-seven thousand, two hundred twenty-one".