127728505 has 8 divisors (see below), whose sum is σ = 153630792. Its totient is φ = 101945088.

The previous prime is 127728481. The next prime is 127728511. The reversal of 127728505 is 505827721.

It can be written as a sum of positive squares in 4 ways, for example, as 1750329 + 125978176 = 1323^2 + 11224^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 127728505 - 2⁵ = 127728473 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27334 + ... + 31663.

It is an arithmetic number, because the mean of its divisors is an integer number (19203849).

Almost surely, 2^127728505 is an apocalyptic number.

It is an amenable number.

127728505 is a deficient number, since it is larger than the sum of its proper divisors (25902287).

127728505 is an equidigital number, since it uses as much as digits as its factorization.

127728505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59435.

The product of its (nonzero) digits is 39200, while the sum is 37.

The square root of 127728505 is about 11301.7036326388. The cubic root of 127728505 is about 503.6118528797.

The spelling of 127728505 in words is "one hundred twenty-seven million, seven hundred twenty-eight thousand, five hundred five".