256689743 has 2 divisors, whose sum is σ = 256689744. Its totient is φ = 256689742.

The previous prime is 256689731. The next prime is 256689751. The reversal of 256689743 is 347986652.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256689743 - 2⁶ = 256689679 is a prime.

It is a super-2 number, since 2×256689743² = 131779248322812098, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 256689691 and 256689700.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256689793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128344871 + 128344872.

It is an arithmetic number, because the mean of its divisors is an integer number (128344872).

Almost surely, 2^256689743 is an apocalyptic number.

256689743 is a deficient number, since it is larger than the sum of its proper divisors (1).

256689743 is an equidigital number, since it uses as much as digits as its factorization.

256689743 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2177280, while the sum is 50.

The square root of 256689743 is about 16021.5399696783. The cubic root of 256689743 is about 635.5301691734.

The spelling of 256689743 in words is "two hundred fifty-six million, six hundred eighty-nine thousand, seven hundred forty-three".