127791109807729 has 27 divisors (see below), whose sum is σ = 136145358458851. Its totient is φ = 119925084446720.

The previous prime is 127791109807681. The next prime is 127791109807733. The reversal of 127791109807729 is 927708901197721.

The square root of 127791109807729 is 11304473.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 13 ways, for example, as 24184117530225 + 103606992277504 = 4917735^2 + 10178752^2 .

It is not a de Polignac number, because 127791109807729 - 2²⁵ = 127791076253297 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (127791109907729) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 86287041669 + ... + 86287043149.

Almost surely, 2^{127791109807729} is an apocalyptic number.

127791109807729 is the 11304473-rd square number.

127791109807729 is the 5652237-th centered octagonal number.

It is an amenable number.

127791109807729 is a deficient number, since it is larger than the sum of its proper divisors (8354248651122).

127791109807729 is an frugal number, since it uses more digits than its factorization.

127791109807729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3894 (or 1947 counting only the distinct ones).

The product of its (nonzero) digits is 56010528, while the sum is 70.

The spelling of 127791109807729 in words is "one hundred twenty-seven trillion, seven hundred ninety-one billion, one hundred nine million, eight hundred seven thousand, seven hundred twenty-nine".