256423 has 2 divisors, whose sum is σ = 256424. Its totient is φ = 256422.

The previous prime is 256393. The next prime is 256441. The reversal of 256423 is 324652.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256423 - 2⁵ = 256391 is a prime.

256423 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 256394 and 256403.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256483) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128211 + 128212.

It is an arithmetic number, because the mean of its divisors is an integer number (128212).

2²⁵⁶⁴²³ is an apocalyptic number.

256423 is a deficient number, since it is larger than the sum of its proper divisors (1).

256423 is an equidigital number, since it uses as much as digits as its factorization.

256423 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1440, while the sum is 22.

The square root of 256423 is about 506.3822666721. The cubic root of 256423 is about 63.5309952637.

The spelling of 256423 in words is "two hundred fifty-six thousand, four hundred twenty-three".