685357440 has 128 divisors (see below), whose sum is σ = 2192037120. Its totient is φ = 182138880.

The previous prime is 685357429. The next prime is 685357457. The reversal of 685357440 is 44753586.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-3 number, since 3×685357440³ (a number of 27 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 685357392 and 685357401.

It is a congruent number.

It is an unprimeable number.

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, 942357 + ... + 943083.

It is an arithmetic number, because the mean of its divisors is an integer number (17125290).

Almost surely, 2^685357440 is an apocalyptic number.

685357440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 685357440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1096018560).

685357440 is an abundant number, since it is smaller than the sum of its proper divisors (1506679680).

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

685357440 is a wasteful number, since it uses less digits than its factorization.

685357440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1240 (or 1228 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 42.

The square root of 685357440 is about 26179.3323062297. The cubic root of 685357440 is about 881.6692833035.

The spelling of 685357440 in words is "six hundred eighty-five million, three hundred fifty-seven thousand, four hundred forty".