127721363762866 has 4 divisors (see below), whose sum is σ = 191582045644302. Its totient is φ = 63860681881432.

The previous prime is 127721363762851. The next prime is 127721363762903. The reversal of 127721363762866 is 668267363127721.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 103709354720841 + 24012009042025 = 10183779^2 + 4900205^2 .

It is a super-2 number, since 2×127721363762866² (a number of 29 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (67) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 31930340940715 + ... + 31930340940718.

Almost surely, 2^{127721363762866} is an apocalyptic number.

127721363762866 is a deficient number, since it is larger than the sum of its proper divisors (63860681881436).

127721363762866 is an equidigital number, since it uses as much as digits as its factorization.

127721363762866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63860681881435.

The product of its digits is 256048128, while the sum is 67.

The spelling of 127721363762866 in words is "one hundred twenty-seven trillion, seven hundred twenty-one billion, three hundred sixty-three million, seven hundred sixty-two thousand, eight hundred sixty-six".