128266729 has 2 divisors, whose sum is σ = 128266730. Its totient is φ = 128266728.

The previous prime is 128266709. The next prime is 128266741. The reversal of 128266729 is 927662821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 93161104 + 35105625 = 9652^2 + 5925^2 .

It is a cyclic number.

It is not a de Polignac number, because 128266729 - 2²¹ = 126169577 is a prime.

It is not a weakly prime, because it can be changed into another prime (128266709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64133364 + 64133365.

It is an arithmetic number, because the mean of its divisors is an integer number (64133365).

Almost surely, 2^128266729 is an apocalyptic number.

It is an amenable number.

128266729 is a deficient number, since it is larger than the sum of its proper divisors (1).

128266729 is an equidigital number, since it uses as much as digits as its factorization.

128266729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 43.

The square root of 128266729 is about 11325.4902322151. The cubic root of 128266729 is about 504.3182369619.

The spelling of 128266729 in words is "one hundred twenty-eight million, two hundred sixty-six thousand, seven hundred twenty-nine".