127666157567721 has 8 divisors (see below), whose sum is σ = 170221918043424. Its totient is φ = 85110584401920.

The previous prime is 127666157567713. The next prime is 127666157567723. The reversal of 127666157567721 is 127765751666721.

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

It is not a de Polignac number, because 127666157567721 - 2³ = 127666157567713 is a prime.

It is a super-2 number, since 2×127666157567721² (a number of 29 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (69) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (127666157567723) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45229336 + ... + 47969001.

It is an arithmetic number, because the mean of its divisors is an integer number (21277739755428).

Almost surely, 2^{127666157567721} is an apocalyptic number.

It is an amenable number.

127666157567721 is a deficient number, since it is larger than the sum of its proper divisors (42555760475703).

127666157567721 is an equidigital number, since it uses as much as digits as its factorization.

127666157567721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93654951.

The product of its digits is 311169600, while the sum is 69.

The spelling of 127666157567721 in words is "one hundred twenty-seven trillion, six hundred sixty-six billion, one hundred fifty-seven million, five hundred sixty-seven thousand, seven hundred twenty-one".