3781

3781 is a natural number that comes after 3780 and before 3782. In mathematics, it is an odd composite number and a semiprime, being the product of two primes, 19 and 199. Its prime factorization is 19 × 199, and its divisors are 1, 19, 199, and 3781.

In various base representations, 3781 can be expressed as 0xEC5 in hexadecimal and as 111011000101 in binary. In Roman numerals, it is written as MMMDCCLXXXI. The sum of its digits is 19, so the digital root is 1 and it is not divisible by 3.

As a semiprime, 3781 is not a prime power and is not a perfect square. It is an example often cited in number theory to illustrate the properties of products of two primes and the structure of divisors for semiprimes.

Beyond these mathematical properties, 3781 does not have widely recognized significance in other common contexts. It serves mainly as a numeric example in discussions of factorization, base representations, and related topics in arithmetic.