• 87 can be written using four 4's:
87 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.
It is a semiprime because it is the product of two primes.
It is a cyclic number.
It is an Ulam number.
It is a D-number.
It is an alternating number because its digits alternate between even and odd.
87 is a lucky number.
It is a plaindrome in base 4, base 6, base 8, base 11, base 13, base 15 and base 16.
It is a nialpdrome in base 5, base 10, base 12 and base 14.
It is a congruent number.
87 is a wasteful number, since it uses less digits than its factorization.
87 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 32.
The square root of 87 is about 9.3273790531. The cubic root of 87 is about 4.4310476217.
Multiplying 87 by its reverse (78), we get a triangular number (6786 = T116).