128929777 has 2 divisors, whose sum is σ = 128929778. Its totient is φ = 128929776.

The previous prime is 128929747. The next prime is 128929799. The reversal of 128929777 is 777929821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 112275216 + 16654561 = 10596^2 + 4081^2 .

It is a cyclic number.

It is not a de Polignac number, because 128929777 - 2¹⁹ = 128405489 is a prime.

It is not a weakly prime, because it can be changed into another prime (128929727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64464888 + 64464889.

It is an arithmetic number, because the mean of its divisors is an integer number (64464889).

Almost surely, 2^128929777 is an apocalyptic number.

It is an amenable number.

128929777 is a deficient number, since it is larger than the sum of its proper divisors (1).

128929777 is an equidigital number, since it uses as much as digits as its factorization.

128929777 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 889056, while the sum is 52.

The square root of 128929777 is about 11354.7248755749. The cubic root of 128929777 is about 505.1857330732.

The spelling of 128929777 in words is "one hundred twenty-eight million, nine hundred twenty-nine thousand, seven hundred seventy-seven".