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 an emirpimes, since its reverse is a distinct semiprime: 3523521 = 3 ⋅1174507.
It is a d-powerful number, because it can be written as 1 + 212 + 54 + 39 + 220 + 55 + 311 .
It is a D-number.
It is a Duffinian number.
It is a congruent number.
21253253 is an apocalyptic number.
It is an amenable number.
1253253 is an equidigital number, since it uses as much as digits as its factorization.
1253253 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 417754.
The square root of 1253253 is about 1119.4878293220. The cubic root of 1253253 is about 107.8150985721.
Adding to 1253253 its reverse (3523521), we get a palindrome (4776774).
The spelling of 1253253 in words is "one million, two hundred fifty-three thousand, two hundred fifty-three".