25287209 has 2 divisors, whose sum is σ = 25287210. Its totient is φ = 25287208.

The previous prime is 25287193. The next prime is 25287247. The reversal of 25287209 is 90278252.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19333609 + 5953600 = 4397^2 + 2440^2 .

It is a cyclic number.

It is not a de Polignac number, because 25287209 - 2⁴ = 25287193 is a prime.

It is a plaindrome in base 15.

It is not a weakly prime, because it can be changed into another prime (25257209) 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, 12643604 + 12643605.

It is an arithmetic number, because the mean of its divisors is an integer number (12643605).

Almost surely, 2^25287209 is an apocalyptic number.

It is an amenable number.

25287209 is a deficient number, since it is larger than the sum of its proper divisors (1).

25287209 is an equidigital number, since it uses as much as digits as its factorization.

25287209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 25287209 is about 5028.6388814469. The cubic root of 25287209 is about 293.5172519406.

The spelling of 25287209 in words is "twenty-five million, two hundred eighty-seven thousand, two hundred nine".