256417645447 has 2 divisors, whose sum is σ = 256417645448. Its totient is φ = 256417645446.

The previous prime is 256417645411. The next prime is 256417645571. The reversal of 256417645447 is 744546714652.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 256417645447 - 2¹¹ = 256417643399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256417625447) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128208822723 + 128208822724.

It is an arithmetic number, because the mean of its divisors is an integer number (128208822724).

Almost surely, 2^256417645447 is an apocalyptic number.

256417645447 is a deficient number, since it is larger than the sum of its proper divisors (1).

256417645447 is an equidigital number, since it uses as much as digits as its factorization.

256417645447 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22579200, while the sum is 55.

The spelling of 256417645447 in words is "two hundred fifty-six billion, four hundred seventeen million, six hundred forty-five thousand, four hundred forty-seven".