685565440 has 160 divisors (see below), whose sum is σ = 1909949184. Its totient is φ = 231137280.

The previous prime is 685565437. The next prime is 685565473. The reversal of 685565440 is 44565586.

It is a tau number, because it is divible by the number of its divisors (160).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1200355 + ... + 1200925.

Almost surely, 2^685565440 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 685565440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (954974592).

685565440 is an abundant number, since it is smaller than the sum of its proper divisors (1224383744).

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

685565440 is an equidigital number, since it uses as much as digits as its factorization.

685565440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 668 (or 652 counting only the distinct ones).

The product of its (nonzero) digits is 576000, while the sum is 43.

The square root of 685565440 is about 26183.3046042703. The cubic root of 685565440 is about 881.7584672588.

The spelling of 685565440 in words is "six hundred eighty-five million, five hundred sixty-five thousand, four hundred forty".