687688218 has 80 divisors (see below), whose sum is σ = 1765794624. Its totient is φ = 195955200.

The previous prime is 687688213. The next prime is 687688237. The reversal of 687688218 is 812886786.

687688218 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not an unprimeable number, because it can be changed into a prime (687688213) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 653793 + ... + 654843.

Almost surely, 2^687688218 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 687688218, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (882897312).

687688218 is an abundant number, since it is smaller than the sum of its proper divisors (1078106406).

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

687688218 is a wasteful number, since it uses less digits than its factorization.

687688218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1649 (or 1640 counting only the distinct ones).

The product of its digits is 2064384, while the sum is 54.

The square root of 687688218 is about 26223.8101350662. The cubic root of 687688218 is about 882.6676189193.

The spelling of 687688218 in words is "six hundred eighty-seven million, six hundred eighty-eight thousand, two hundred eighteen".