127985681 has 2 divisors, whose sum is σ = 127985682. Its totient is φ = 127985680.

The previous prime is 127985677. The next prime is 127985699. The reversal of 127985681 is 186589721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76720081 + 51265600 = 8759^2 + 7160^2 .

It is an emirp because it is prime and its reverse (186589721) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 127985681 - 2² = 127985677 is a prime.

It is a super-2 number, since 2×127985681² = 32760669082067522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (127981681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63992840 + 63992841.

It is an arithmetic number, because the mean of its divisors is an integer number (63992841).

Almost surely, 2^127985681 is an apocalyptic number.

It is an amenable number.

127985681 is a deficient number, since it is larger than the sum of its proper divisors (1).

127985681 is an equidigital number, since it uses as much as digits as its factorization.

127985681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 241920, while the sum is 47.

The square root of 127985681 is about 11313.0756649109. The cubic root of 127985681 is about 503.9496267472.

The spelling of 127985681 in words is "one hundred twenty-seven million, nine hundred eighty-five thousand, six hundred eighty-one".