25605109 has 2 divisors, whose sum is σ = 25605110. Its totient is φ = 25605108.

The previous prime is 25605091. The next prime is 25605119. The reversal of 25605109 is 90150652.

Together with previous prime (25605091) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16990884 + 8614225 = 4122^2 + 2935^2 .

It is a cyclic number.

It is not a de Polignac number, because 25605109 - 2¹⁷ = 25474037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25605119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12802554 + 12802555.

It is an arithmetic number, because the mean of its divisors is an integer number (12802555).

Almost surely, 2^25605109 is an apocalyptic number.

It is an amenable number.

25605109 is a deficient number, since it is larger than the sum of its proper divisors (1).

25605109 is an equidigital number, since it uses as much as digits as its factorization.

25605109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2700, while the sum is 28.

The square root of 25605109 is about 5060.1491084750. The cubic root of 25605109 is about 294.7421245423.

The spelling of 25605109 in words is "twenty-five million, six hundred five thousand, one hundred nine".