28960221 has 4 divisors (see below), whose sum is σ = 38613632. Its totient is φ = 19306812.

The previous prime is 28960219. The next prime is 28960249. The reversal of 28960221 is 12206982.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 28960221 - 2¹ = 28960219 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 (28960021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4826701 + ... + 4826706.

It is an arithmetic number, because the mean of its divisors is an integer number (9653408).

Almost surely, 2^28960221 is an apocalyptic number.

It is an amenable number.

28960221 is a deficient number, since it is larger than the sum of its proper divisors (9653411).

28960221 is an equidigital number, since it uses as much as digits as its factorization.

28960221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9653410.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 28960221 is about 5381.4701522911. The cubic root of 28960221 is about 307.0911427831.

The spelling of 28960221 in words is "twenty-eight million, nine hundred sixty thousand, two hundred twenty-one".