77947681768868 has 6 divisors (see below), whose sum is σ = 136408443095526. Its totient is φ = 38973840884432.

The previous prime is 77947681768823. The next prime is 77947681768903. The reversal of 77947681768868 is 86886718674977.

It can be written as a sum of positive squares in only one way, i.e., 66373315708324 + 11574366060544 = 8146982^2 + 3402112^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9743460221105 + ... + 9743460221112.

It is an arithmetic number, because the mean of its divisors is an integer number (22734740515921).

Almost surely, 2^{77947681768868} is an apocalyptic number.

It is an amenable number.

77947681768868 is a deficient number, since it is larger than the sum of its proper divisors (58460761326658).

77947681768868 is a wasteful number, since it uses less digits than its factorization.

77947681768868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19486920442221 (or 19486920442219 counting only the distinct ones).

The product of its digits is 76473040896, while the sum is 92.

The spelling of 77947681768868 in words is "seventy-seven trillion, nine hundred forty-seven billion, six hundred eighty-one million, seven hundred sixty-eight thousand, eight hundred sixty-eight".