687938 has 12 divisors (see below), whose sum is σ = 1071330. Its totient is φ = 331296.

The previous prime is 687931. The next prime is 687949. The reversal of 687938 is 839786.

It can be written as a sum of positive squares in 3 ways, for example, as 677329 + 10609 = 823^2 + 103^2 .

It is a super-3 number, since 3×687938³ = 976717913849333016, which contains 333 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 687895 and 687904.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 687938.

It is not an unprimeable number, because it can be changed into a prime (687931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1478 + ... + 1886.

2⁶⁸⁷⁹³⁸ is an apocalyptic number.

687938 is a deficient number, since it is larger than the sum of its proper divisors (383392).

687938 is a wasteful number, since it uses less digits than its factorization.

687938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 469 (or 440 counting only the distinct ones).

The product of its digits is 72576, while the sum is 41.

The square root of 687938 is about 829.4202794724. The cubic root of 687938 is about 88.2774473445.

The spelling of 687938 in words is "six hundred eighty-seven thousand, nine hundred thirty-eight".