256517413647343 has 2 divisors, whose sum is σ = 256517413647344. Its totient is φ = 256517413647342.

The previous prime is 256517413647301. The next prime is 256517413647353. The reversal of 256517413647343 is 343746314715652.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 256517413647343 - 2¹⁷ = 256517413516271 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256517413647353) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128258706823671 + 128258706823672.

It is an arithmetic number, because the mean of its divisors is an integer number (128258706823672).

Almost surely, 2^{256517413647343} is an apocalyptic number.

256517413647343 is a deficient number, since it is larger than the sum of its proper divisors (1).

256517413647343 is an equidigital number, since it uses as much as digits as its factorization.

256517413647343 is an evil number, because the sum of its binary digits is even.

The product of its digits is 152409600, while the sum is 61.

The spelling of 256517413647343 in words is "two hundred fifty-six trillion, five hundred seventeen billion, four hundred thirteen million, six hundred forty-seven thousand, three hundred forty-three".