128505679 has 2 divisors, whose sum is σ = 128505680. Its totient is φ = 128505678.

The previous prime is 128505677. The next prime is 128505733. The reversal of 128505679 is 976505821.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 128505679 - 2¹ = 128505677 is a prime.

Together with 128505677, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128505673) 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, 64252839 + 64252840.

It is an arithmetic number, because the mean of its divisors is an integer number (64252840).

Almost surely, 2^128505679 is an apocalyptic number.

128505679 is a deficient number, since it is larger than the sum of its proper divisors (1).

128505679 is an equidigital number, since it uses as much as digits as its factorization.

128505679 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 151200, while the sum is 43.

The square root of 128505679 is about 11336.0345359389. The cubic root of 128505679 is about 504.6312100134.

The spelling of 128505679 in words is "one hundred twenty-eight million, five hundred five thousand, six hundred seventy-nine".