685988173 has 4 divisors (see below), whose sum is σ = 738756508. Its totient is φ = 633219840.

The previous prime is 685988167. The next prime is 685988189. The reversal of 685988173 is 371889586.

685988173 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 362635849 + 323352324 = 19043^2 + 17982^2 .

It is a cyclic number.

It is not a de Polignac number, because 685988173 - 2⁹ = 685987661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685988153) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26384148 + ... + 26384173.

It is an arithmetic number, because the mean of its divisors is an integer number (184689127).

Almost surely, 2^685988173 is an apocalyptic number.

It is an amenable number.

685988173 is a deficient number, since it is larger than the sum of its proper divisors (52768335).

685988173 is a wasteful number, since it uses less digits than its factorization.

685988173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52768334.

The product of its digits is 2903040, while the sum is 55.

The square root of 685988173 is about 26191.3759279653. The cubic root of 685988173 is about 881.9396665006.

The spelling of 685988173 in words is "six hundred eighty-five million, nine hundred eighty-eight thousand, one hundred seventy-three".