687240865584 has 320 divisors, whose sum is σ = 2464105620480. Its totient is φ = 178544424960.

The previous prime is 687240865583. The next prime is 687240865603. The reversal of 687240865584 is 485568042786.

687240865584 is a `hidden beast` number, since 6 + 8 + 7 + 2 + 40 + 8 + 6 + 5 + 584 = 666.

It is a super-2 number, since 2×687240865584² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (687240865583) by changing a digit.

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 63 ways as a sum of consecutive naturals, for example, 2503444 + ... + 2764364.

It is an arithmetic number, because the mean of its divisors is an integer number (7700330064).

Almost surely, 2^687240865584 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 687240865584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1232052810240).

687240865584 is an abundant number, since it is smaller than the sum of its proper divisors (1776864754896).

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

687240865584 is a wasteful number, since it uses less digits than its factorization.

687240865584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 261025 (or 261013 counting only the distinct ones).

The product of its (nonzero) digits is 103219200, while the sum is 63.

The spelling of 687240865584 in words is "six hundred eighty-seven billion, two hundred forty million, eight hundred sixty-five thousand, five hundred eighty-four".