685515655440 has 2880 divisors, whose sum is σ = 3319467540480. Its totient is φ = 128098713600.

The previous prime is 685515655381. The next prime is 685515655459. The reversal of 685515655440 is 44556515586.

685515655440 is a `hidden beast` number, since 6 + 85 + 5 + 1 + 5 + 6 + 554 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 575 ways as a sum of consecutive naturals, for example, 8677413321 + ... + 8677413399.

It is an arithmetic number, because the mean of its divisors is an integer number (1152592896).

Almost surely, 2^685515655440 is an apocalyptic number.

685515655440 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 685515655440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1659733770240).

685515655440 is an abundant number, since it is smaller than the sum of its proper divisors (2633951885040).

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

685515655440 is a wasteful number, since it uses less digits than its factorization.

685515655440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184 (or 155 counting only the distinct ones).

The product of its (nonzero) digits is 14400000, while the sum is 54.

The spelling of 685515655440 in words is "six hundred eighty-five billion, five hundred fifteen million, six hundred fifty-five thousand, four hundred forty".