687281840 has 60 divisors (see below), whose sum is σ = 1858827456. Its totient is φ = 235638144.

The previous prime is 687281807. The next prime is 687281849. The reversal of 687281840 is 48182786.

687281840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 687281791 and 687281800.

It is not an unprimeable number, because it can be changed into a prime (687281849) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 83744 + ... + 91583.

Almost surely, 2^687281840 is an apocalyptic number.

It is an amenable number.

687281840 is an abundant number, since it is smaller than the sum of its proper divisors (1171545616).

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

687281840 is a wasteful number, since it uses less digits than its factorization.

687281840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175354 (or 175341 counting only the distinct ones).

The product of its (nonzero) digits is 172032, while the sum is 44.

The square root of 687281840 is about 26216.0607262037. The cubic root of 687281840 is about 882.4937187075.

The spelling of 687281840 in words is "six hundred eighty-seven million, two hundred eighty-one thousand, eight hundred forty".