686390979775 has 24 divisors (see below), whose sum is σ = 900950125680. Its totient is φ = 517848119040.

The previous prime is 686390979773. The next prime is 686390979787. The reversal of 686390979775 is 577979093686.

It is not a de Polignac number, because 686390979775 - 2¹ = 686390979773 is a prime.

It is a super-2 number, since 2×686390979775² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686390979773) 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 23 ways as a sum of consecutive naturals, for example, 10977502 + ... + 11039851.

It is an arithmetic number, because the mean of its divisors is an integer number (37539588570).

Almost surely, 2^686390979775 is an apocalyptic number.

686390979775 is a deficient number, since it is larger than the sum of its proper divisors (214559145905).

686390979775 is a wasteful number, since it uses less digits than its factorization.

686390979775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22017435 (or 22017430 counting only the distinct ones).

The product of its (nonzero) digits is 1080203040, while the sum is 76.

The spelling of 686390979775 in words is "six hundred eighty-six billion, three hundred ninety million, nine hundred seventy-nine thousand, seven hundred seventy-five".