77755271861 has 2 divisors, whose sum is σ = 77755271862. Its totient is φ = 77755271860.

The previous prime is 77755271849. The next prime is 77755271899. The reversal of 77755271861 is 16817255777.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44055491236 + 33699780625 = 209894^2 + 183575^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77755271861 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 77755271797 and 77755271806.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77755271831) 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, 38877635930 + 38877635931.

It is an arithmetic number, because the mean of its divisors is an integer number (38877635931).

Almost surely, 2^77755271861 is an apocalyptic number.

It is an amenable number.

77755271861 is a deficient number, since it is larger than the sum of its proper divisors (1).

77755271861 is an equidigital number, since it uses as much as digits as its factorization.

77755271861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5762400, while the sum is 56.

The spelling of 77755271861 in words is "seventy-seven billion, seven hundred fifty-five million, two hundred seventy-one thousand, eight hundred sixty-one".