256213 has 4 divisors (see below), whose sum is σ = 257868. Its totient is φ = 254560.

The previous prime is 256211. The next prime is 256219. The reversal of 256213 is 312652.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 178929 + 77284 = 423^2 + 278^2 .

It is a cyclic number.

It is not a de Polignac number, because 256213 - 2¹ = 256211 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256211) 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 3 ways as a sum of consecutive naturals, for example, 568 + ... + 913.

It is an arithmetic number, because the mean of its divisors is an integer number (64467).

2²⁵⁶²¹³ is an apocalyptic number.

It is an amenable number.

256213 is a deficient number, since it is larger than the sum of its proper divisors (1655).

256213 is a wasteful number, since it uses less digits than its factorization.

256213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1654.

The product of its digits is 360, while the sum is 19.

The square root of 256213 is about 506.1748709685. The cubic root of 256213 is about 63.5136474273.

Adding to 256213 its reverse (312652), we get a palindrome (568865).

The spelling of 256213 in words is "two hundred fifty-six thousand, two hundred thirteen".