28126321 has 4 divisors (see below), whose sum is σ = 28252672. Its totient is φ = 27999972.

The previous prime is 28126297. The next prime is 28126333. The reversal of 28126321 is 12362182.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28126321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28126361) 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, 62841 + ... + 63286.

It is an arithmetic number, because the mean of its divisors is an integer number (7063168).

Almost surely, 2^28126321 is an apocalyptic number.

It is an amenable number.

28126321 is a deficient number, since it is larger than the sum of its proper divisors (126351).

28126321 is a wasteful number, since it uses less digits than its factorization.

28126321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126350.

The product of its digits is 1152, while the sum is 25.

The square root of 28126321 is about 5303.4254025111. The cubic root of 28126321 is about 304.1148609420.

The spelling of 28126321 in words is "twenty-eight million, one hundred twenty-six thousand, three hundred twenty-one".