687538 has 4 divisors (see below), whose sum is σ = 1031310. Its totient is φ = 343768.

The previous prime is 687523. The next prime is 687541. The reversal of 687538 is 835786.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 660969 + 26569 = 813^2 + 163^2 .

It is a junction number, because it is equal to n+sod(n) for n = 687497 and 687506.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 171883 + ... + 171886.

2⁶⁸⁷⁵³⁸ is an apocalyptic number.

687538 is a deficient number, since it is larger than the sum of its proper divisors (343772).

687538 is a wasteful number, since it uses less digits than its factorization.

687538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343771.

The product of its digits is 40320, while the sum is 37.

The square root of 687538 is about 829.1791121344. The cubic root of 687538 is about 88.2603344530.

It can be divided in two parts, 687 and 538, that added together give a triangular number (1225 = T₄₉).

The spelling of 687538 in words is "six hundred eighty-seven thousand, five hundred thirty-eight".