257217 has 8 divisors (see below), whose sum is σ = 347424. Its totient is φ = 169248.

The previous prime is 257189. The next prime is 257219. The reversal of 257217 is 712752.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 257217 - 2¹⁵ = 224449 is a prime.

257217 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (257219) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 268 + ... + 765.

It is an arithmetic number, because the mean of its divisors is an integer number (43428).

2²⁵⁷²¹⁷ is an apocalyptic number.

It is an amenable number.

257217 is a deficient number, since it is larger than the sum of its proper divisors (90207).

257217 is a wasteful number, since it uses less digits than its factorization.

257217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1119.

The product of its digits is 980, while the sum is 24.

The square root of 257217 is about 507.1656534112. The cubic root of 257217 is about 63.5965011326.

Adding to 257217 its reverse (712752), we get a palindrome (969969).

Subtracting 257217 from its reverse (712752), we obtain a triangular number (455535 = T₉₅₄).

It can be divided in two parts, 257 and 217, that added together give a palindrome (474).

The spelling of 257217 in words is "two hundred fifty-seven thousand, two hundred seventeen".