687631680 has 336 divisors, whose sum is σ = 2529596160. Its totient is φ = 177666048.

The previous prime is 687631649. The next prime is 687631723. The reversal of 687631680 is 86136786.

687631680 is a `hidden beast` number, since 6 + 8 + 7 + 631 + 6 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2877001 + ... + 2877239.

It is an arithmetic number, because the mean of its divisors is an integer number (7528560).

Almost surely, 2^687631680 is an apocalyptic number.

687631680 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 687631680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1264798080).

687631680 is an abundant number, since it is smaller than the sum of its proper divisors (1841964480).

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

687631680 is a wasteful number, since it uses less digits than its factorization.

687631680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308 (or 286 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 687631680 is about 26222.7321231027. The cubic root of 687631680 is about 882.6434288730.

The spelling of 687631680 in words is "six hundred eighty-seven million, six hundred thirty-one thousand, six hundred eighty".