127785265581217 has 2 divisors, whose sum is σ = 127785265581218. Its totient is φ = 127785265581216.

The previous prime is 127785265581109. The next prime is 127785265581283. The reversal of 127785265581217 is 712185562587721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 120919141512976 + 6866124068241 = 10996324^2 + 2620329^2 .

It is a cyclic number.

It is not a de Polignac number, because 127785265581217 - 2¹⁵ = 127785265548449 is a prime.

It is not a weakly prime, because it can be changed into another prime (127785265581317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63892632790608 + 63892632790609.

It is an arithmetic number, because the mean of its divisors is an integer number (63892632790609).

Almost surely, 2^{127785265581217} is an apocalyptic number.

It is an amenable number.

127785265581217 is a deficient number, since it is larger than the sum of its proper divisors (1).

127785265581217 is an equidigital number, since it uses as much as digits as its factorization.

127785265581217 is an evil number, because the sum of its binary digits is even.

The product of its digits is 131712000, while the sum is 67.

The spelling of 127785265581217 in words is "one hundred twenty-seven trillion, seven hundred eighty-five billion, two hundred sixty-five million, five hundred eighty-one thousand, two hundred seventeen".