127818281561 has 2 divisors, whose sum is σ = 127818281562. Its totient is φ = 127818281560.

The previous prime is 127818281491. The next prime is 127818281573. The reversal of 127818281561 is 165182818721.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69831233536 + 57987048025 = 264256^2 + 240805^2 .

It is a cyclic number.

It is not a de Polignac number, because 127818281561 - 2³⁴ = 110638412377 is a prime.

It is not a weakly prime, because it can be changed into another prime (127818281581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 63909140780 + 63909140781.

It is an arithmetic number, because the mean of its divisors is an integer number (63909140781).

Almost surely, 2^127818281561 is an apocalyptic number.

It is an amenable number.

127818281561 is a deficient number, since it is larger than the sum of its proper divisors (1).

127818281561 is an equidigital number, since it uses as much as digits as its factorization.

127818281561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 430080, while the sum is 50.

The spelling of 127818281561 in words is "one hundred twenty-seven billion, eight hundred eighteen million, two hundred eighty-one thousand, five hundred sixty-one".