77968158721 has 8 divisors (see below), whose sum is σ = 80490312104. Its totient is φ = 75467842560.

The previous prime is 77968158701. The next prime is 77968158731. The reversal of 77968158721 is 12785186977.

It can be written as a sum of positive squares in 4 ways, for example, as 21393157696 + 56575001025 = 146264^2 + 237855^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 77968158721 - 2⁹ = 77968158209 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 77968158721.

It is not an unprimeable number, because it can be changed into a prime (77968158701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5452050 + ... + 5466331.

It is an arithmetic number, because the mean of its divisors is an integer number (10061289013).

Almost surely, 2^77968158721 is an apocalyptic number.

It is an amenable number.

77968158721 is a deficient number, since it is larger than the sum of its proper divisors (2522153383).

77968158721 is a wasteful number, since it uses less digits than its factorization.

77968158721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10918611.

The product of its digits is 11854080, while the sum is 61.

The spelling of 77968158721 in words is "seventy-seven billion, nine hundred sixty-eight million, one hundred fifty-eight thousand, seven hundred twenty-one".