128005729 has 2 divisors, whose sum is σ = 128005730. Its totient is φ = 128005728.

The previous prime is 128005723. The next prime is 128005747. The reversal of 128005729 is 927500821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 124211025 + 3794704 = 11145^2 + 1948^2 .

It is a cyclic number.

It is not a de Polignac number, because 128005729 - 2⁷ = 128005601 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 128005694 and 128005703.

It is not a weakly prime, because it can be changed into another prime (128005723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64002864 + 64002865.

It is an arithmetic number, because the mean of its divisors is an integer number (64002865).

Almost surely, 2^128005729 is an apocalyptic number.

It is an amenable number.

128005729 is a deficient number, since it is larger than the sum of its proper divisors (1).

128005729 is an equidigital number, since it uses as much as digits as its factorization.

128005729 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 128005729 is about 11313.9616845736. The cubic root of 128005729 is about 503.9759386871.

The spelling of 128005729 in words is "one hundred twenty-eight million, five thousand, seven hundred twenty-nine".