686543904 has 96 divisors (see below), whose sum is σ = 2007008640. Its totient is φ = 228324096.

The previous prime is 686543881. The next prime is 686543909. The reversal of 686543904 is 409345686.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×686543904² = 942685064239122432, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 686543904.

It is not an unprimeable number, because it can be changed into a prime (686543909) 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 15 ways as a sum of consecutive naturals, for example, 627582 + ... + 628674.

It is an arithmetic number, because the mean of its divisors is an integer number (20906340).

Almost surely, 2^686543904 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 686543904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1003504320).

686543904 is an abundant number, since it is smaller than the sum of its proper divisors (1320464736).

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

686543904 is a wasteful number, since it uses less digits than its factorization.

686543904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1839 (or 1825 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The square root of 686543904 is about 26201.9828257329. The cubic root of 686543904 is about 882.1777604599.

The spelling of 686543904 in words is "six hundred eighty-six million, five hundred forty-three thousand, nine hundred four".