28290209 has 2 divisors, whose sum is σ = 28290210. Its totient is φ = 28290208.

The previous prime is 28290203. The next prime is 28290217. The reversal of 28290209 is 90209282.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25150225 + 3139984 = 5015^2 + 1772^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28290209 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28290203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14145104 + 14145105.

It is an arithmetic number, because the mean of its divisors is an integer number (14145105).

Almost surely, 2^28290209 is an apocalyptic number.

It is an amenable number.

28290209 is a deficient number, since it is larger than the sum of its proper divisors (1).

28290209 is an equidigital number, since it uses as much as digits as its factorization.

28290209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 28290209 is about 5318.8541059142. The cubic root of 28290209 is about 304.7043951306.

The spelling of 28290209 in words is "twenty-eight million, two hundred ninety thousand, two hundred nine".