77665656791 has 2 divisors, whose sum is σ = 77665656792. Its totient is φ = 77665656790.

The previous prime is 77665656667. The next prime is 77665656797. The reversal of 77665656791 is 19765656677.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77665656791 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77665656797) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38832828395 + 38832828396.

It is an arithmetic number, because the mean of its divisors is an integer number (38832828396).

Almost surely, 2^77665656791 is an apocalyptic number.

77665656791 is a deficient number, since it is larger than the sum of its proper divisors (1).

77665656791 is an equidigital number, since it uses as much as digits as its factorization.

77665656791 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 100018800, while the sum is 65.

The spelling of 77665656791 in words is "seventy-seven billion, six hundred sixty-five million, six hundred fifty-six thousand, seven hundred ninety-one".