256537 has 4 divisors (see below), whose sum is σ = 262836. Its totient is φ = 250240.

The previous prime is 256517. The next prime is 256541. The reversal of 256537 is 735652.

256537 is nontrivially palindromic in base 13.

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 143641 + 112896 = 379^2 + 336^2 .

It is a cyclic number.

It is not a de Polignac number, because 256537 - 2¹¹ = 254489 is a prime.

It is a super-2 number, since 2×256537² = 131622464738, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256517) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3088 + ... + 3169.

It is an arithmetic number, because the mean of its divisors is an integer number (65709).

2²⁵⁶⁵³⁷ is an apocalyptic number.

It is an amenable number.

256537 is a deficient number, since it is larger than the sum of its proper divisors (6299).

256537 is an equidigital number, since it uses as much as digits as its factorization.

256537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6298.

The product of its digits is 6300, while the sum is 28.

The square root of 256537 is about 506.4948173476. The cubic root of 256537 is about 63.5404086944.

The spelling of 256537 in words is "two hundred fifty-six thousand, five hundred thirty-seven".