256426 has 4 divisors (see below), whose sum is σ = 384642. Its totient is φ = 128212.

The previous prime is 256423. The next prime is 256441. The reversal of 256426 is 624652.

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

It can be written as a sum of positive squares in only one way, i.e., 133225 + 123201 = 365^2 + 351^2 .

It is a super-3 number, since 3×256426³ = 50583331376630328, which contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 256426.

It is not an unprimeable number, because it can be changed into a prime (256423) 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 as a sum of consecutive naturals, namely, 64105 + ... + 64108.

2²⁵⁶⁴²⁶ is an apocalyptic number.

256426 is a deficient number, since it is larger than the sum of its proper divisors (128216).

256426 is a wasteful number, since it uses less digits than its factorization.

256426 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128215.

The product of its digits is 2880, while the sum is 25.

The square root of 256426 is about 506.3852288525. The cubic root of 256426 is about 63.5312430213.

The spelling of 256426 in words is "two hundred fifty-six thousand, four hundred twenty-six".