128677729 has 2 divisors, whose sum is σ = 128677730. Its totient is φ = 128677728.

The previous prime is 128677697. The next prime is 128677751. The reversal of 128677729 is 927776821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 114062400 + 14615329 = 10680^2 + 3823^2 .

It is a cyclic number.

It is not a de Polignac number, because 128677729 - 2⁵ = 128677697 is a prime.

It is not a weakly prime, because it can be changed into another prime (128677789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64338864 + 64338865.

It is an arithmetic number, because the mean of its divisors is an integer number (64338865).

Almost surely, 2^128677729 is an apocalyptic number.

It is an amenable number.

128677729 is a deficient number, since it is larger than the sum of its proper divisors (1).

128677729 is an equidigital number, since it uses as much as digits as its factorization.

128677729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 592704, while the sum is 49.

The square root of 128677729 is about 11343.6206301163. The cubic root of 128677729 is about 504.8563183043.

The spelling of 128677729 in words is "one hundred twenty-eight million, six hundred seventy-seven thousand, seven hundred twenty-nine".