77646717056 has 16 divisors (see below), whose sum is σ = 154686819390. Its totient is φ = 38823358464.

The previous prime is 77646717053. The next prime is 77646717059. The reversal of 77646717056 is 65071764677.

It is an interprime number because it is at equal distance from previous prime (77646717053) and next prime (77646717059).

It can be written as a sum of positive squares in only one way, i.e., 64333249600 + 13313467456 = 253640^2 + 115384^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is a junction number, because it is equal to n+sod(n) for n = 77646716992 and 77646717010.

It is not an unprimeable number, because it can be changed into a prime (77646717053) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 303307361 + ... + 303307616.

Almost surely, 2^77646717056 is an apocalyptic number.

It is an amenable number.

77646717056 is a deficient number, since it is larger than the sum of its proper divisors (77040102334).

77646717056 is an equidigital number, since it uses as much as digits as its factorization.

77646717056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 606614991 (or 606614979 counting only the distinct ones).

The product of its (nonzero) digits is 10372320, while the sum is 56.

The spelling of 77646717056 in words is "seventy-seven billion, six hundred forty-six million, seven hundred seventeen thousand, fifty-six".