28205189 has 2 divisors, whose sum is σ = 28205190. Its totient is φ = 28205188.

The previous prime is 28205183. The next prime is 28205231. The reversal of 28205189 is 98150282.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26604964 + 1600225 = 5158^2 + 1265^2 .

It is a cyclic number.

It is not a de Polignac number, because 28205189 - 2⁴ = 28205173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28205183) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14102594 + 14102595.

It is an arithmetic number, because the mean of its divisors is an integer number (14102595).

Almost surely, 2^28205189 is an apocalyptic number.

It is an amenable number.

28205189 is a deficient number, since it is larger than the sum of its proper divisors (1).

28205189 is an equidigital number, since it uses as much as digits as its factorization.

28205189 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 28205189 is about 5310.8557690828. The cubic root of 28205189 is about 304.3988481638.

The spelling of 28205189 in words is "twenty-eight million, two hundred five thousand, one hundred eighty-nine".