127728817 has 8 divisors (see below), whose sum is σ = 130997160. Its totient is φ = 124467840.

The previous prime is 127728761. The next prime is 127728823. The reversal of 127728817 is 718827721.

It can be written as a sum of positive squares in 4 ways, for example, as 3272481 + 124456336 = 1809^2 + 11156^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-127728817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (127728827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55159 + ... + 57427.

It is an arithmetic number, because the mean of its divisors is an integer number (16374645).

Almost surely, 2^127728817 is an apocalyptic number.

It is an amenable number.

127728817 is a deficient number, since it is larger than the sum of its proper divisors (3268343).

127728817 is a wasteful number, since it uses less digits than its factorization.

127728817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3683.

The product of its digits is 87808, while the sum is 43.

The square root of 127728817 is about 11301.7174358590. The cubic root of 127728817 is about 503.6122629338.

The spelling of 127728817 in words is "one hundred twenty-seven million, seven hundred twenty-eight thousand, eight hundred seventeen".