28252009 has 2 divisors, whose sum is σ = 28252010. Its totient is φ = 28252008.

The previous prime is 28251961. The next prime is 28252013. The reversal of 28252009 is 90025282.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23736384 + 4515625 = 4872^2 + 2125^2 .

It is a cyclic number.

It is not a de Polignac number, because 28252009 - 2⁹ = 28251497 is a prime.

It is not a weakly prime, because it can be changed into another prime (58252009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14126004 + 14126005.

It is an arithmetic number, because the mean of its divisors is an integer number (14126005).

Almost surely, 2^28252009 is an apocalyptic number.

It is an amenable number.

28252009 is a deficient number, since it is larger than the sum of its proper divisors (1).

28252009 is an equidigital number, since it uses as much as digits as its factorization.

28252009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 28252009 is about 5315.2618938299. The cubic root of 28252009 is about 304.5671868734.

The spelling of 28252009 in words is "twenty-eight million, two hundred fifty-two thousand, nine".