685782891666 has 64 divisors (see below), whose sum is σ = 1613725027200. Its totient is φ = 215131811328.

The previous prime is 685782891659. The next prime is 685782891671. The reversal of 685782891666 is 666198287586.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 685782891594 and 685782891603.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 23856390 + ... + 23885118.

It is an arithmetic number, because the mean of its divisors is an integer number (25214453550).

Almost surely, 2^685782891666 is an apocalyptic number.

685782891666 is an abundant number, since it is smaller than the sum of its proper divisors (927942135534).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

685782891666 is a wasteful number, since it uses less digits than its factorization.

685782891666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54760 (or 54754 counting only the distinct ones).

The product of its digits is 418037760, while the sum is 72.

The spelling of 685782891666 in words is "six hundred eighty-five billion, seven hundred eighty-two million, eight hundred ninety-one thousand, six hundred sixty-six".