1255257217 has 4 divisors (see below), whose sum is σ = 1255960660. Its totient is φ = 1254553776.

The previous prime is 1255257193. The next prime is 1255257251. The reversal of 1255257217 is 7127525521.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7127525521 = 1601 ⋅4451921.

It can be written as a sum of positive squares in 2 ways, for example, as 739785601 + 515471616 = 27199^2 + 22704^2 .

It is a cyclic number.

It is not a de Polignac number, because 1255257217 - 2⁷ = 1255257089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1255257617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 349038 + ... + 352615.

It is an arithmetic number, because the mean of its divisors is an integer number (313990165).

Almost surely, 2^1255257217 is an apocalyptic number.

It is an amenable number.

1255257217 is a deficient number, since it is larger than the sum of its proper divisors (703443).

1255257217 is an equidigital number, since it uses as much as digits as its factorization.

1255257217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 703442.

The product of its digits is 49000, while the sum is 37.

The square root of 1255257217 is about 35429.6093260990. The cubic root of 1255257217 is about 1078.7254102179.

The spelling of 1255257217 in words is "one billion, two hundred fifty-five million, two hundred fifty-seven thousand, two hundred seventeen".