77786355886681 has 8 divisors (see below), whose sum is σ = 83770476865544. Its totient is φ = 71802314213760.

The previous prime is 77786355886649. The next prime is 77786355886711. The reversal of 77786355886681 is 18668855368777.

It can be written as a sum of positive squares in 4 ways, for example, as 8417779598281 + 69368576288400 = 2901341^2 + 8328780^2 .

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

It is not a de Polignac number, because 77786355886681 - 2⁵ = 77786355886649 is a prime.

It is a super-2 number, since 2×77786355886681² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77786355886621) 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 in 7 ways as a sum of consecutive naturals, for example, 17781540 + ... + 21719941.

It is an arithmetic number, because the mean of its divisors is an integer number (10471309608193).

Almost surely, 2^{77786355886681} is an apocalyptic number.

It is an amenable number.

77786355886681 is a deficient number, since it is larger than the sum of its proper divisors (5984120978863).

77786355886681 is a wasteful number, since it uses less digits than its factorization.

77786355886681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39652971.

The product of its digits is 22759833600, while the sum is 85.

The spelling of 77786355886681 in words is "seventy-seven trillion, seven hundred eighty-six billion, three hundred fifty-five million, eight hundred eighty-six thousand, six hundred eighty-one".