• 253 can be written using four 4's:
253 is nontrivially palindromic in base 12 and base 14.
It is the 7-th star number.
253 is an esthetic number in base 11, because in such base its adjacent digits differ by 1.
It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.
253 is an idoneal number.
It is an Ulam number.
It is a Duffinian number.
253 is an undulating number in base 12 and base 14.
It is a plaindrome in base 13 and base 15.
It is a nialpdrome in base 4, base 7, base 9, base 11 and base 16.
It is a congruent number.
253 is a gapful number since it is divisible by the number (23) formed by its first and last digit.
253 is the 22-nd triangular number.
It is an amenable number.
253 is a wasteful number, since it uses less digits than its factorization.
253 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 34.
The square root of 253 is about 15.9059737206. The cubic root of 253 is about 6.3247035434.
Subtracting from 253 its sum of digits (10), we obtain a 5-th power (243 = 35).
Subtracting 253 from its reverse (352), we obtain a palindrome (99).
The spelling of 253 in words is "two hundred fifty-three", and thus it is an aban number.