77785386317 has 4 divisors (see below), whose sum is σ = 78262597440. Its totient is φ = 77308175196.

The previous prime is 77785386257. The next prime is 77785386331. The reversal of 77785386317 is 71368358777.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 71368358777 = 233 ⋅306301969.

It is a cyclic number.

It is not a de Polignac number, because 77785386317 - 2¹⁴ = 77785369933 is a prime.

It is a super-4 number, since 4×77785386317⁴ (a number of 45 digits) contains 4444 as substring.

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 77785386317.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77785386517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 238605317 + ... + 238605642.

It is an arithmetic number, because the mean of its divisors is an integer number (19565649360).

Almost surely, 2^77785386317 is an apocalyptic number.

It is an amenable number.

77785386317 is a deficient number, since it is larger than the sum of its proper divisors (477211123).

77785386317 is a wasteful number, since it uses less digits than its factorization.

77785386317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 477211122.

The product of its digits is 41489280, while the sum is 62.

The spelling of 77785386317 in words is "seventy-seven billion, seven hundred eighty-five million, three hundred eighty-six thousand, three hundred seventeen".