77780717808085 has 8 divisors (see below), whose sum is σ = 93336934239576. Its totient is φ = 62224525666560.

The previous prime is 77780717808077. The next prime is 77780717808149. The reversal of 77780717808085 is 58080871708777.

It can be written as a sum of positive squares in 4 ways, for example, as 40731851386801 + 37048866421284 = 6382151^2 + 6086778^2 .

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

It is not a de Polignac number, because 77780717808085 - 2³ = 77780717808077 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 77780717807999 and 77780717808017.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1931337 + ... + 12621073.

It is an arithmetic number, because the mean of its divisors is an integer number (11667116779947).

Almost surely, 2^{77780717808085} is an apocalyptic number.

It is an amenable number.

77780717808085 is a deficient number, since it is larger than the sum of its proper divisors (15556216431491).

77780717808085 is a wasteful number, since it uses less digits than its factorization.

77780717808085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12144983.

The product of its (nonzero) digits is 344207360, while the sum is 73.

The spelling of 77780717808085 in words is "seventy-seven trillion, seven hundred eighty billion, seven hundred seventeen million, eight hundred eight thousand, eighty-five".