127681 has 2 divisors, whose sum is σ = 127682. Its totient is φ = 127680.

The previous prime is 127679. The next prime is 127691. The reversal of 127681 is 186721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 102400 + 25281 = 320^2 + 159^2 .

It is a cyclic number.

It is not a de Polignac number, because 127681 - 2¹ = 127679 is a prime.

It is a super-2 number, since 2×127681² = 32604875522, which contains 22 as substring.

Together with 127679, it forms a pair of twin primes.

127681 is a lucky number.

It is equal to p₁₁₉₅₉ and since 127681 and 11959 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (127601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63840 + 63841.

It is an arithmetic number, because the mean of its divisors is an integer number (63841).

2¹²⁷⁶⁸¹ is an apocalyptic number.

It is an amenable number.

127681 is a deficient number, since it is larger than the sum of its proper divisors (1).

127681 is an equidigital number, since it uses as much as digits as its factorization.

127681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 672, while the sum is 25.

The square root of 127681 is about 357.3247822360. The cubic root of 127681 is about 50.3549410416.

It can be divided in two parts, 12768 and 1, that added together give a square (12769 = 113²).

The spelling of 127681 in words is "one hundred twenty-seven thousand, six hundred eighty-one".