28288121 has 2 divisors, whose sum is σ = 28288122. Its totient is φ = 28288120.

The previous prime is 28288087. The next prime is 28288147. The reversal of 28288121 is 12188282.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17977600 + 10310521 = 4240^2 + 3211^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28288121 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28288621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14144060 + 14144061.

It is an arithmetic number, because the mean of its divisors is an integer number (14144061).

Almost surely, 2^28288121 is an apocalyptic number.

It is an amenable number.

28288121 is a deficient number, since it is larger than the sum of its proper divisors (1).

28288121 is an equidigital number, since it uses as much as digits as its factorization.

28288121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4096, while the sum is 32.

The square root of 28288121 is about 5318.6578194127. The cubic root of 28288121 is about 304.6968985626.

The spelling of 28288121 in words is "twenty-eight million, two hundred eighty-eight thousand, one hundred twenty-one".