687278656 has 63 divisors (see below), whose sum is σ = 1425078811. Its totient is φ = 328853504.

The previous prime is 687278633. The next prime is 687278671. The reversal of 687278656 is 656872786.

The square root of 687278656 is 26216.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 237160000 + 450118656 = 15400^2 + 21216^2 .

It is a Duffinian number.

Its product of digits (6773760) is a multiple of the sum of its prime divisors (144).

It is a junction number, because it is equal to n+sod(n) for n = 687278597 and 687278606.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 6082056 + ... + 6082168.

Almost surely, 2^687278656 is an apocalyptic number.

687278656 is the 26216-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 687278656

687278656 is an abundant number, since it is smaller than the sum of its proper divisors (737800155).

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

687278656 is an equidigital number, since it uses as much as digits as its factorization.

687278656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296 (or 144 counting only the distinct ones).

The product of its digits is 6773760, while the sum is 55.

The cubic root of 687278656 is about 882.4923559166.

The spelling of 687278656 in words is "six hundred eighty-seven million, two hundred seventy-eight thousand, six hundred fifty-six".