27768861161 has 2 divisors, whose sum is σ = 27768861162. Its totient is φ = 27768861160.

The previous prime is 27768861149. The next prime is 27768861199. The reversal of 27768861161 is 16116886772.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26843545600 + 925315561 = 163840^2 + 30419^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27768861161 is a prime.

It is a super-2 number, since 2×27768861161² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (27768861961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13884430580 + 13884430581.

It is an arithmetic number, because the mean of its divisors is an integer number (13884430581).

Almost surely, 2^27768861161 is an apocalyptic number.

It is an amenable number.

27768861161 is a deficient number, since it is larger than the sum of its proper divisors (1).

27768861161 is an equidigital number, since it uses as much as digits as its factorization.

27768861161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1354752, while the sum is 53.

The spelling of 27768861161 in words is "twenty-seven billion, seven hundred sixty-eight million, eight hundred sixty-one thousand, one hundred sixty-one".