128772689 has 2 divisors, whose sum is σ = 128772690. Its totient is φ = 128772688.

The previous prime is 128772661. The next prime is 128772719. The reversal of 128772689 is 986277821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 121374289 + 7398400 = 11017^2 + 2720^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-128772689 is a prime.

It is not a weakly prime, because it can be changed into another prime (128772619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64386344 + 64386345.

It is an arithmetic number, because the mean of its divisors is an integer number (64386345).

Almost surely, 2^128772689 is an apocalyptic number.

It is an amenable number.

128772689 is a deficient number, since it is larger than the sum of its proper divisors (1).

128772689 is an equidigital number, since it uses as much as digits as its factorization.

128772689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 677376, while the sum is 50.

The square root of 128772689 is about 11347.8054706626. The cubic root of 128772689 is about 504.9804769762.

The spelling of 128772689 in words is "one hundred twenty-eight million, seven hundred seventy-two thousand, six hundred eighty-nine".