256417 has 6 divisors (see below), whose sum is σ = 298338. Its totient is φ = 219744.

The previous prime is 256393. The next prime is 256423. The reversal of 256417 is 714652.

It can be written as a sum of positive squares in only one way, i.e., 254016 + 2401 = 504^2 + 49^2 .

It is not a de Polignac number, because 256417 - 2¹¹ = 254369 is a prime.

It is a Duffinian number.

256417 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 256391 and 256400.

It is not an unprimeable number, because it can be changed into a prime (256117) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2568 + ... + 2665.

It is an arithmetic number, because the mean of its divisors is an integer number (49723).

2²⁵⁶⁴¹⁷ is an apocalyptic number.

It is an amenable number.

256417 is a deficient number, since it is larger than the sum of its proper divisors (41921).

256417 is an equidigital number, since it uses as much as digits as its factorization.

256417 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5247 (or 5240 counting only the distinct ones).

The product of its digits is 1680, while the sum is 25.

The square root of 256417 is about 506.3763422594. The cubic root of 256417 is about 63.5304997427.

The spelling of 256417 in words is "two hundred fifty-six thousand, four hundred seventeen".