28128161 has 2 divisors, whose sum is σ = 28128162. Its totient is φ = 28128160.

The previous prime is 28128109. The next prime is 28128181. The reversal of 28128161 is 16182182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20647936 + 7480225 = 4544^2 + 2735^2 .

It is a cyclic number.

It is not a de Polignac number, because 28128161 - 2¹⁸ = 27866017 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28128101) 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 as a sum of consecutive naturals, namely, 14064080 + 14064081.

It is an arithmetic number, because the mean of its divisors is an integer number (14064081).

Almost surely, 2^28128161 is an apocalyptic number.

It is an amenable number.

28128161 is a deficient number, since it is larger than the sum of its proper divisors (1).

28128161 is an equidigital number, since it uses as much as digits as its factorization.

28128161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1536, while the sum is 29.

The square root of 28128161 is about 5303.5988724639. The cubic root of 28128161 is about 304.1214924425.

The spelling of 28128161 in words is "twenty-eight million, one hundred twenty-eight thousand, one hundred sixty-one".