128247878989 has 2 divisors, whose sum is σ = 128247878990. Its totient is φ = 128247878988.

The previous prime is 128247878971. The next prime is 128247878999. The reversal of 128247878989 is 989878742821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 112414690089 + 15833188900 = 335283^2 + 125830^2 .

It is a cyclic number.

It is not a de Polignac number, because 128247878989 - 2⁹ = 128247878477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128247878999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64123939494 + 64123939495.

It is an arithmetic number, because the mean of its divisors is an integer number (64123939495).

Almost surely, 2^128247878989 is an apocalyptic number.

It is an amenable number.

128247878989 is a deficient number, since it is larger than the sum of its proper divisors (1).

128247878989 is an equidigital number, since it uses as much as digits as its factorization.

128247878989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 260112384, while the sum is 73.

The spelling of 128247878989 in words is "one hundred twenty-eight billion, two hundred forty-seven million, eight hundred seventy-eight thousand, nine hundred eighty-nine".