The definition of 25 is a number that comes after 24 and before 26. It is an even number, meaning it can be divided by two without leaving a remainder. It has four divisors: 1, 5, 10 and 25 itself. In the decimal system (base-10), it represents the value twenty-five; in binary (base 2) it is represented as 11001; in hexadecimal (base 16) its representation is 19; and finally in Roman numerals its representation would be XXV.

25 has been used throughout history to represent various things such as age or time periods of significance – for example Jesus Christ was believed to have died at the age of 25 according to some Christian traditions or historically significant events such as when Julius Caesar crossed The Rubicon river with his army which marked his entrance into Rome’s civil war at age 25 years old. Furthermore, in mathematics, it holds special properties such as being both composite numbers and square numbers.

In conclusion, 25 holds many different meanings throughout history depending on context but primarily stands for numerical values from base ten systems up through roman numerals representing ‘twenty five’.

Additionally, due to certain mathematical properties associated with this particular number, it also carries additional importance within mathematics circles making it not only important culturally but mathematically too!