687240 has 96 divisors (see below), whose sum is σ = 2358720. Its totient is φ = 173184.

The previous prime is 687233. The next prime is 687277. The reversal of 687240 is 42786.

It is a Cunningham number, because it is equal to 829²-1.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8239 + ... + 8321.

It is an arithmetic number, because the mean of its divisors is an integer number (24570).

2⁶⁸⁷²⁴⁰ is an apocalyptic number.

687240 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 687240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1179360).

687240 is an abundant number, since it is smaller than the sum of its proper divisors (1671480).

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

687240 is a wasteful number, since it uses less digits than its factorization.

687240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123 (or 116 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 687240 is about 828.9993968635. Note that the first 3 decimals coincide. The cubic root of 687240 is about 88.2475810340.

The spelling of 687240 in words is "six hundred eighty-seven thousand, two hundred forty".