28197289 has 2 divisors, whose sum is σ = 28197290. Its totient is φ = 28197288.

The previous prime is 28197277. The next prime is 28197343. The reversal of 28197289 is 98279182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26347689 + 1849600 = 5133^2 + 1360^2 .

It is a cyclic number.

It is not a de Polignac number, because 28197289 - 2¹⁷ = 28066217 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28197209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14098644 + 14098645.

It is an arithmetic number, because the mean of its divisors is an integer number (14098645).

Almost surely, 2^28197289 is an apocalyptic number.

It is an amenable number.

28197289 is a deficient number, since it is larger than the sum of its proper divisors (1).

28197289 is an equidigital number, since it uses as much as digits as its factorization.

28197289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 145152, while the sum is 46.

The square root of 28197289 is about 5310.1119573885. Note that the first 3 decimals coincide. The cubic root of 28197289 is about 304.3704257879.

The spelling of 28197289 in words is "twenty-eight million, one hundred ninety-seven thousand, two hundred eighty-nine".