647706471257 has 2 divisors, whose sum is σ = 647706471258. Its totient is φ = 647706471256.

The previous prime is 647706471233. The next prime is 647706471317. The reversal of 647706471257 is 752174607746.

647706471257 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 626913984841 + 20792486416 = 791779^2 + 144196^2 .

It is a cyclic number.

It is not a de Polignac number, because 647706471257 - 2³⁰ = 646632729433 is a prime.

It is not a weakly prime, because it can be changed into another prime (647706471227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323853235628 + 323853235629.

It is an arithmetic number, because the mean of its divisors is an integer number (323853235629).

Almost surely, 2^647706471257 is an apocalyptic number.

It is an amenable number.

647706471257 is a deficient number, since it is larger than the sum of its proper divisors (1).

647706471257 is an equidigital number, since it uses as much as digits as its factorization.

647706471257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13829760, while the sum is 56.

The spelling of 647706471257 in words is "six hundred forty-seven billion, seven hundred six million, four hundred seventy-one thousand, two hundred fifty-seven".