687406720 has 512 divisors, whose sum is σ = 2344204800. Its totient is φ = 185794560.

The previous prime is 687406711. The next prime is 687406723. The reversal of 687406720 is 27604786.

687406720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×687406720³ (a number of 27 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (687406723) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 18578542 + ... + 18578578.

It is an arithmetic number, because the mean of its divisors is an integer number (4578525).

Almost surely, 2^687406720 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 687406720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1172102400).

687406720 is an abundant number, since it is smaller than the sum of its proper divisors (1656798080).

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

687406720 is a wasteful number, since it uses less digits than its factorization.

687406720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116 (or 104 counting only the distinct ones).

The product of its (nonzero) digits is 112896, while the sum is 40.

The square root of 687406720 is about 26218.4423641070. The cubic root of 687406720 is about 882.5471655542.

The spelling of 687406720 in words is "six hundred eighty-seven million, four hundred six thousand, seven hundred twenty".