128685438727 has 2 divisors, whose sum is σ = 128685438728. Its totient is φ = 128685438726.

The previous prime is 128685438691. The next prime is 128685438733. The reversal of 128685438727 is 727834586821.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128685438727 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128685438757) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64342719363 + 64342719364.

It is an arithmetic number, because the mean of its divisors is an integer number (64342719364).

Almost surely, 2^128685438727 is an apocalyptic number.

128685438727 is a deficient number, since it is larger than the sum of its proper divisors (1).

128685438727 is an equidigital number, since it uses as much as digits as its factorization.

128685438727 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36126720, while the sum is 61.

The spelling of 128685438727 in words is "one hundred twenty-eight billion, six hundred eighty-five million, four hundred thirty-eight thousand, seven hundred twenty-seven".