127665889 has 4 divisors (see below), whose sum is σ = 137486356. Its totient is φ = 117845424.

The previous prime is 127665823. The next prime is 127665899. The reversal of 127665889 is 988566721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 988566721 = 23879 ⋅41399.

It can be written as a sum of positive squares in 2 ways, for example, as 71115489 + 56550400 = 8433^2 + 7520^2 .

It is a cyclic number.

It is not a de Polignac number, because 127665889 - 2¹¹ = 127663841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (127665899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4910214 + ... + 4910239.

It is an arithmetic number, because the mean of its divisors is an integer number (34371589).

Almost surely, 2^127665889 is an apocalyptic number.

It is an amenable number.

127665889 is a deficient number, since it is larger than the sum of its proper divisors (9820467).

127665889 is an equidigital number, since it uses as much as digits as its factorization.

127665889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9820466.

The product of its digits is 1451520, while the sum is 52.

The square root of 127665889 is about 11298.9330912259. The cubic root of 127665889 is about 503.5295446689.

The spelling of 127665889 in words is "one hundred twenty-seven million, six hundred sixty-five thousand, eight hundred eighty-nine".