• 155 can be written using four 4's:
155 is nontrivially palindromic in base 11.
155 is an esthetic number in base 4 and base 13, because in such bases its adjacent digits differ by 1.
It is a nude number because it is divisible by every one of its digits.
It is an Ulam number.
It is a house number.
It is a Duffinian number.
155 is an undulating number in base 11.
It is a plaindrome in base 8, base 10, base 13 and base 16.
It is a nialpdrome in base 5, base 7, base 14 and base 15.
155 is an equidigital number, since it uses as much as digits as its factorization.
155 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 36.
The square root of 155 is about 12.4498995980. The cubic root of 155 is about 5.3716853549.
Subtracting from 155 its sum of digits (11), we obtain a square (144 = 122).
The spelling of 155 in words is "one hundred fifty-five", and thus it is an aban number.