77681968979 has 4 divisors (see below), whose sum is σ = 82251496584. Its totient is φ = 73112441376.

The previous prime is 77681968967. The next prime is 77681968981. The reversal of 77681968979 is 97986918677.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 77681968979 - 2⁴ = 77681968963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77681968279) 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 in 3 ways as a sum of consecutive naturals, for example, 2284763777 + ... + 2284763810.

It is an arithmetic number, because the mean of its divisors is an integer number (20562874146).

Almost surely, 2^77681968979 is an apocalyptic number.

77681968979 is a deficient number, since it is larger than the sum of its proper divisors (4569527605).

77681968979 is a wasteful number, since it uses less digits than its factorization.

77681968979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4569527604.

The product of its digits is 576108288, while the sum is 77.

The spelling of 77681968979 in words is "seventy-seven billion, six hundred eighty-one million, nine hundred sixty-eight thousand, nine hundred seventy-nine".