• 215 can be written using four 4's:
215 is nontrivially palindromic in base 4 and base 6.
It is a semiprime because it is the product of two primes.
It is a cyclic number.
It is a Duffinian number.
215 is a nontrivial repdigit in base 6.
It is a plaindrome in base 6, base 9, base 12, base 13 and base 14.
It is a nialpdrome in base 6, base 15 and base 16.
It is a zygodrome in base 6.
It is a congruent number.
215 is an equidigital number, since it uses as much as digits as its factorization.
215 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 48.
The square root of 215 is about 14.6628782986. The cubic root of 215 is about 5.9907264149.
Adding to 215 its product of digits (10), we get a square (225 = 152).
Adding to 215 its reverse (512), we get a palindrome (727).
The spelling of 215 in words is "two hundred fifteen", and thus it is an aban number.