28825221 has 4 divisors (see below), whose sum is σ = 38433632. Its totient is φ = 19216812.

The previous prime is 28825213. The next prime is 28825229. The reversal of 28825221 is 12252882.

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 an interprime number because it is at equal distance from previous prime (28825213) and next prime (28825229).

It is not a de Polignac number, because 28825221 - 2³ = 28825213 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 (28825229) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4804201 + ... + 4804206.

It is an arithmetic number, because the mean of its divisors is an integer number (9608408).

Almost surely, 2^28825221 is an apocalyptic number.

It is an amenable number.

28825221 is a deficient number, since it is larger than the sum of its proper divisors (9608411).

28825221 is an equidigital number, since it uses as much as digits as its factorization.

28825221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9608410.

The product of its digits is 5120, while the sum is 30.

The square root of 28825221 is about 5368.9124597073. The cubic root of 28825221 is about 306.6132241203.

The spelling of 28825221 in words is "twenty-eight million, eight hundred twenty-five thousand, two hundred twenty-one".