685438944 has 96 divisors (see below), whose sum is σ = 1857131136. Its totient is φ = 221253120.

The previous prime is 685438933. The next prime is 685438951. The reversal of 685438944 is 449834586.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 391479 + ... + 393225.

It is an arithmetic number, because the mean of its divisors is an integer number (19345116).

Almost surely, 2^685438944 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 685438944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (928565568).

685438944 is an abundant number, since it is smaller than the sum of its proper divisors (1171692192).

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

685438944 is a wasteful number, since it uses less digits than its factorization.

685438944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1888 (or 1880 counting only the distinct ones).

The product of its digits is 3317760, while the sum is 51.

The square root of 685438944 is about 26180.8889077510. Note that the first 3 decimals coincide. The cubic root of 685438944 is about 881.7042318431.

The spelling of 685438944 in words is "six hundred eighty-five million, four hundred thirty-eight thousand, nine hundred forty-four".