684813640 has 32 divisors (see below), whose sum is σ = 1760950080. Its totient is φ = 234793152.

The previous prime is 684813629. The next prime is 684813643. The reversal of 684813640 is 46318486.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 684813593 and 684813602.

It is not an unprimeable number, because it can be changed into a prime (684813643) 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 7 ways as a sum of consecutive naturals, for example, 1222602 + ... + 1223161.

It is an arithmetic number, because the mean of its divisors is an integer number (55029690).

Almost surely, 2^684813640 is an apocalyptic number.

It is an amenable number.

684813640 is an abundant number, since it is smaller than the sum of its proper divisors (1076136440).

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

684813640 is a wasteful number, since it uses less digits than its factorization.

684813640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2445781 (or 2445777 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 40.

The square root of 684813640 is about 26168.9441896306. The cubic root of 684813640 is about 881.4360334245.

The spelling of 684813640 in words is "six hundred eighty-four million, eight hundred thirteen thousand, six hundred forty".