127656721 has 2 divisors, whose sum is σ = 127656722. Its totient is φ = 127656720.

The previous prime is 127656703. The next prime is 127656743.

127656721 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., 71571600 + 56085121 = 8460^2 + 7489^2 .

It is a palprime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-127656721 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (127656751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63828360 + 63828361.

It is an arithmetic number, because the mean of its divisors is an integer number (63828361).

Almost surely, 2^127656721 is an apocalyptic number.

It is an amenable number.

127656721 is a deficient number, since it is larger than the sum of its proper divisors (1).

127656721 is an equidigital number, since it uses as much as digits as its factorization.

127656721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35280, while the sum is 37.

The square root of 127656721 is about 11298.5273819202. The cubic root of 127656721 is about 503.5174911507.

The spelling of 127656721 in words is "one hundred twenty-seven million, six hundred fifty-six thousand, seven hundred twenty-one".