256705543 has 2 divisors, whose sum is σ = 256705544. Its totient is φ = 256705542.

The previous prime is 256705529. The next prime is 256705567. The reversal of 256705543 is 345507652.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-256705543 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256705843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128352771 + 128352772.

It is an arithmetic number, because the mean of its divisors is an integer number (128352772).

Almost surely, 2^256705543 is an apocalyptic number.

256705543 is a deficient number, since it is larger than the sum of its proper divisors (1).

256705543 is an equidigital number, since it uses as much as digits as its factorization.

256705543 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 126000, while the sum is 37.

The square root of 256705543 is about 16022.0330482745. The cubic root of 256705543 is about 635.5432084824.

It can be divided in two parts, 25670 and 5543, that added together give a palindrome (31213).

The spelling of 256705543 in words is "two hundred fifty-six million, seven hundred five thousand, five hundred forty-three".