256489 has 2 divisors, whose sum is σ = 256490. Its totient is φ = 256488.

The previous prime is 256483. The next prime is 256493. The reversal of 256489 is 984652.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 176400 + 80089 = 420^2 + 283^2 .

It is a cyclic number.

It is not a de Polignac number, because 256489 - 2⁹ = 255977 is a prime.

256489 is a lucky 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, 128244 + 128245.

It is an arithmetic number, because the mean of its divisors is an integer number (128245).

2²⁵⁶⁴⁸⁹ is an apocalyptic number.

It is an amenable number.

256489 is a deficient number, since it is larger than the sum of its proper divisors (1).

256489 is an equidigital number, since it uses as much as digits as its factorization.

256489 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 34.

The square root of 256489 is about 506.4474306382. The cubic root of 256489 is about 63.5364454846.

The spelling of 256489 in words is "two hundred fifty-six thousand, four hundred eighty-nine".