685643140 has 72 divisors (see below), whose sum is σ = 1781922240. Its totient is φ = 216987264.

The previous prime is 685643137. The next prime is 685643141. The reversal of 685643140 is 41346586.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 685643140.

It is not an unprimeable number, because it can be changed into a prime (685643141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9171 + ... + 38149.

It is an arithmetic number, because the mean of its divisors is an integer number (24748920).

Almost surely, 2^685643140 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 685643140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (890961120).

685643140 is an abundant number, since it is smaller than the sum of its proper divisors (1096279100).

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

685643140 is a wasteful number, since it uses less digits than its factorization.

685643140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29021 (or 29006 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 37.

The square root of 685643140 is about 26184.7883321596. The cubic root of 685643140 is about 881.7917779834.

The spelling of 685643140 in words is "six hundred eighty-five million, six hundred forty-three thousand, one hundred forty".