28208197 has 2 divisors, whose sum is σ = 28208198. Its totient is φ = 28208196.

The previous prime is 28208183. The next prime is 28208203. The reversal of 28208197 is 79180282.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21659716 + 6548481 = 4654^2 + 2559^2 .

It is a cyclic number.

It is not a de Polignac number, because 28208197 - 2⁷ = 28208069 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28208107) 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, 14104098 + 14104099.

It is an arithmetic number, because the mean of its divisors is an integer number (14104099).

Almost surely, 2^28208197 is an apocalyptic number.

It is an amenable number.

28208197 is a deficient number, since it is larger than the sum of its proper divisors (1).

28208197 is an equidigital number, since it uses as much as digits as its factorization.

28208197 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 28208197 is about 5311.1389550642. The cubic root of 28208197 is about 304.4096688582.

The spelling of 28208197 in words is "twenty-eight million, two hundred eight thousand, one hundred ninety-seven".