28253321 has 4 divisors (see below), whose sum is σ = 28264452. Its totient is φ = 28242192.

The previous prime is 28253273. The next prime is 28253327. The reversal of 28253321 is 12335282.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 23145721 + 5107600 = 4811^2 + 2260^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28253321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28253327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 311 + ... + 7523.

It is an arithmetic number, because the mean of its divisors is an integer number (7066113).

Almost surely, 2^28253321 is an apocalyptic number.

It is an amenable number.

28253321 is a deficient number, since it is larger than the sum of its proper divisors (11131).

28253321 is an equidigital number, since it uses as much as digits as its factorization.

28253321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11130.

The product of its digits is 2880, while the sum is 26.

The square root of 28253321 is about 5315.3853105866. The cubic root of 28253321 is about 304.5719014167.

The spelling of 28253321 in words is "twenty-eight million, two hundred fifty-three thousand, three hundred twenty-one".