127686721 has 2 divisors, whose sum is σ = 127686722. Its totient is φ = 127686720.

The previous prime is 127686719. The next prime is 127686743.

127686721 is nontrivially palindromic in base 10.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84640000 + 43046721 = 9200^2 + 6561^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 127686721 - 2¹ = 127686719 is a prime.

Together with 127686719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (127686761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63843360 + 63843361.

It is an arithmetic number, because the mean of its divisors is an integer number (63843361).

Almost surely, 2^127686721 is an apocalyptic number.

It is an amenable number.

127686721 is a deficient number, since it is larger than the sum of its proper divisors (1).

127686721 is an equidigital number, since it uses as much as digits as its factorization.

127686721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56448, while the sum is 40.

The square root of 127686721 is about 11299.8549105730. The cubic root of 127686721 is about 503.5569311464.

The spelling of 127686721 in words is "one hundred twenty-seven million, six hundred eighty-six thousand, seven hundred twenty-one".