127968521 has 4 divisors (see below), whose sum is σ = 128135700. Its totient is φ = 127801344.

The previous prime is 127968509. The next prime is 127968551. The reversal of 127968521 is 125869721.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 125869721 = 241 ⋅522281.

It can be written as a sum of positive squares in 2 ways, for example, as 24641296 + 103327225 = 4964^2 + 10165^2 .

It is a cyclic number.

It is not a de Polignac number, because 127968521 - 2¹⁸ = 127706377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (127968551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82436 + ... + 83973.

It is an arithmetic number, because the mean of its divisors is an integer number (32033925).

Almost surely, 2^127968521 is an apocalyptic number.

It is an amenable number.

127968521 is a deficient number, since it is larger than the sum of its proper divisors (167179).

127968521 is an equidigital number, since it uses as much as digits as its factorization.

127968521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167178.

The product of its digits is 60480, while the sum is 41.

The square root of 127968521 is about 11312.3172250428. The cubic root of 127968521 is about 503.9271029721.

The spelling of 127968521 in words is "one hundred twenty-seven million, nine hundred sixty-eight thousand, five hundred twenty-one".