It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 7831 = 41 ⋅191.
It is a 4-Lehmer number, since φ(1387) divides (1387-1)4.
It is a cyclic number.
It is an Ulam number.
It is a Duffinian number.
1387 is a lucky number.
It is a plaindrome in base 4 and base 16.
It is a nialpdrome in base 12 and base 14.
It is a congruent number.
It is a Poulet number, since it divides 21386-1.
1387 is the 19-th decagonal number.
1387 is the 22-nd hex number.
1387 is an equidigital number, since it uses as much as digits as its factorization.
1387 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 92.
The square root of 1387 is about 37.2424488991. The cubic root of 1387 is about 11.1521556022.
The spelling of 1387 in words is "one thousand, three hundred eighty-seven".