256613 has 6 divisors (see below), whose sum is σ = 298566. Its totient is φ = 219912.

The previous prime is 256609. The next prime is 256639. The reversal of 256613 is 316652.

It can be written as a sum of positive squares in only one way, i.e., 247009 + 9604 = 497^2 + 98^2 .

It is not a de Polignac number, because 256613 - 2² = 256609 is a prime.

It is a d-powerful number, because it can be written as 2³ + 5⁷ + 6² + 6⁴ + 1 + 3¹¹ .

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2570 + ... + 2667.

It is an arithmetic number, because the mean of its divisors is an integer number (49761).

2²⁵⁶⁶¹³ is an apocalyptic number.

It is an amenable number.

256613 is a deficient number, since it is larger than the sum of its proper divisors (41953).

256613 is an equidigital number, since it uses as much as digits as its factorization.

256613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5251 (or 5244 counting only the distinct ones).

The product of its digits is 1080, while the sum is 23.

The square root of 256613 is about 506.5698372387. The cubic root of 256613 is about 63.5466827656.

The spelling of 256613 in words is "two hundred fifty-six thousand, six hundred thirteen".