2587

2587 is an integer in the decimal numbering system. It is the natural number that follows 2586 and precedes 2588, placing it within the range of four-digit numbers.

In mathematics, 2587 is odd and composite. It factors as 13 × 199, making it a semiprime—the product of two distinct primes—and it is square-free (no repeated prime factors). The positive divisors of 2587 are 1, 13, 199, and 2587, giving it four divisors in total. Euler’s totient function yields φ(2587) = (13 − 1)(199 − 1) = 12 × 198 = 2376. In modular arithmetic, 2587 is congruent to 3 modulo 4. In base representations, 2587 equals 101000011011 in binary and A1B in hexadecimal. In Roman numerals, it is written as MMDLXXXVII.

If used as a year, 2587 would lie in the 26th century of the Anno Domini era, a distant future in historical terms. Beyond this calendrical usage, 2587 is primarily notable in number theory as a semiprime with the prime factors 13 and 199, and it serves as an example of the properties and representations that accompany composite numbers with two distinct prime factors.