127689731569 has 9 divisors (see below), whose sum is σ = 131953074201. Its totient is φ = 123559987860.

The previous prime is 127689731503. The next prime is 127689731579. The reversal of 127689731569 is 965137986721.

The square root of 127689731569 is 357337.

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

It is not a de Polignac number, because 127689731569 - 2¹⁷ = 127689600497 is a prime.

It is a super-2 number, since 2×127689731569² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 127689731569.

It is not an unprimeable number, because it can be changed into a prime (127689731579) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 11071684 + ... + 11083210.

It is an arithmetic number, because the mean of its divisors is an integer number (14661452689).

Almost surely, 2^127689731569 is an apocalyptic number.

127689731569 is the 357337-th square number.

127689731569 is the 178669-th centered octagonal number.

It is an amenable number.

127689731569 is a deficient number, since it is larger than the sum of its proper divisors (4263342632).

127689731569 is an frugal number, since it uses more digits than its factorization.

127689731569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23116 (or 11558 counting only the distinct ones).

The product of its digits is 34292160, while the sum is 64.

Multiplying 127689731569 by its sum of digits (64), we get a square (8172142820416 = 2858696²).

The spelling of 127689731569 in words is "one hundred twenty-seven billion, six hundred eighty-nine million, seven hundred thirty-one thousand, five hundred sixty-nine".