6687771281 has 2 divisors, whose sum is σ = 6687771282. Its totient is φ = 6687771280.

The previous prime is 6687771263. The next prime is 6687771283. The reversal of 6687771281 is 1821777866.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4558410256 + 2129361025 = 67516^2 + 46145^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6687771281 is a prime.

It is a super-2 number, since 2×6687771281² = 89452569413936761922, which contains 22 as substring.

Together with 6687771283, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (6687771283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3343885640 + 3343885641.

It is an arithmetic number, because the mean of its divisors is an integer number (3343885641).

Almost surely, 2^6687771281 is an apocalyptic number.

It is an amenable number.

6687771281 is a deficient number, since it is larger than the sum of its proper divisors (1).

6687771281 is an equidigital number, since it uses as much as digits as its factorization.

6687771281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1580544, while the sum is 53.

The square root of 6687771281 is about 81778.7948125919. The cubic root of 6687771281 is about 1884.0559859768.

The spelling of 6687771281 in words is "six billion, six hundred eighty-seven million, seven hundred seventy-one thousand, two hundred eighty-one".