2501

2501 = 41 x 61.

2501 is the product of the only two primes (41 and 61) that can be the last two digits of a perfect fourth power. If you replace the 5 by a 4, you get a fourth power: 2401 = 7⁴.

2501 is a pentagonal number, having the form n(3n – 1)/2. In this case, n = 41.

2501 has two representations as a sum of two squares: 2501 = 1² + 50² = 10² + 49².

2501 is the hypotenuse of two primitive Pythagorean triples: 2501² = 100² + 2499² = 980² + 2301².


Project 2501, from the film and manga Ghost in the Shell, is an artificial intelligence program that develops sapience.

Source: Prime Curios!