685980686 has 4 divisors (see below), whose sum is σ = 1028971032. Its totient is φ = 342990342.

The previous prime is 685980649. The next prime is 685980689. The reversal of 685980686 is 686089586.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685980689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 171495170 + ... + 171495173.

It is an arithmetic number, because the mean of its divisors is an integer number (257242758).

Almost surely, 2^685980686 is an apocalyptic number.

685980686 is a deficient number, since it is larger than the sum of its proper divisors (342990346).

685980686 is a wasteful number, since it uses less digits than its factorization.

685980686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342990345.

The product of its (nonzero) digits is 4976640, while the sum is 56.

The square root of 685980686 is about 26191.2329988491. The cubic root of 685980686 is about 881.9364579388.

Subtracting 685980686 from its reverse (686089586), we obtain a square (108900 = 330²).

The spelling of 685980686 in words is "six hundred eighty-five million, nine hundred eighty thousand, six hundred eighty-six".