25 (twenty-five) is the natural number following 24 and preceding 26.
It is a square number, being 52 = 5 × 5. It is the smallest square that is also a sum of two (non-zero) squares: 25 = 32 + 42. Hence it often appears in illustrations of the Pythagorean theorem.
25 is a centered octagonal number, a centered square number, and an automorphic number.
25 percent (%) is equal to 1/4.
25 has an aliquot sum of 6 and number 6 is the first (or smallest) number to have an aliquot sequence that does not culminate in 0 through a prime. Twenty-five is the aliquot sum of three integers; 95, 119, and 143. Twenty-five is the second composite member of the 6-aliquot tree.
It is the smallest base 10 Friedman number as it can be expressed by its own numbers: 52.
It is also a Cullen number. 25 is the smallest pseudoprime satisfying the congruence 7n = 7 mod n.
25 is the smallest aspiring number — a composite non-sociable number whose aliquot sequence does not terminate.
According to the Shapiro inequality, 25 is the least odd integer n such that there exist x1, x2, …, xn such that
We'll be fighting in the streets
With our children at our feet
And the morals that they worship will be gone
And the men who spurred us on
Sit in judgement of all wrong
They decide and the shotgun sings the song
I'll tip my hat to the new constitution
Take a bow for the new revolution
Smile and grin at the change all around
Pick up my guitar and play
Just like yesterday
Then I'll get on my knees and pray
We don't get fooled again
The change, it had to come
We knew it all along
We were liberated from the fold, that's all
And the world looks just the same
And history ain't changed
'Cause the banners, they are flown in the next war
I'll tip my hat to the new constitution
Take a bow for the new revolution
Smile and grin at the change all around
Pick up my guitar and play
Just like yesterday
Then I'll get on my knees and pray
We don't get fooled again
No, no!
I'll move myself and my family aside
If we happen to be left half alive
I'll get all my papers and smile at the sky
Though I know that the hypnotized never lie
Do ya?
There's nothing in the streets
Looks any different to me
And the slogans are replaced, by-the-bye
And the parting on the left
Are now parting on the right
And the beards have all grown longer overnight
I'll tip my hat to the new constitution
Take a bow for the new revolution
Smile and grin at the change all around
Pick up my guitar and play
Just like yesterday
Then I'll get on my knees and pray
We don't get fooled again
Don't get fooled again
No, no!
Yeaaaaaaaaaaaaaaaaaaaaaaaaah!
Meet the new boss
Same as the old boss