687776 has 12 divisors (see below), whose sum is σ = 1354122. Its totient is φ = 343872.

The previous prime is 687773. The next prime is 687779. The reversal of 687776 is 677786.

687776 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (687773) and next prime (687779).

It can be written as a sum of positive squares in only one way, i.e., 672400 + 15376 = 820^2 + 124^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 687776.

It is not an unprimeable number, because it can be changed into a prime (687773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10715 + ... + 10778.

2⁶⁸⁷⁷⁷⁶ is an apocalyptic number.

It is an amenable number.

687776 is a deficient number, since it is larger than the sum of its proper divisors (666346).

687776 is a wasteful number, since it uses less digits than its factorization.

687776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21503 (or 21495 counting only the distinct ones).

The product of its digits is 98784, while the sum is 41.

The square root of 687776 is about 829.3226151505. The cubic root of 687776 is about 88.2705174229.

The spelling of 687776 in words is "six hundred eighty-seven thousand, seven hundred seventy-six".