687542 has 4 divisors (see below), whose sum is σ = 1031316. Its totient is φ = 343770.

The previous prime is 687541. The next prime is 687551. The reversal of 687542 is 245786.

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

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 687499 and 687508.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 687542.

It is not an unprimeable number, because it can be changed into a prime (687541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 171884 + ... + 171887.

It is an arithmetic number, because the mean of its divisors is an integer number (257829).

2⁶⁸⁷⁵⁴² is an apocalyptic number.

687542 is a deficient number, since it is larger than the sum of its proper divisors (343774).

687542 is a wasteful number, since it uses less digits than its factorization.

687542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 343773.

The product of its digits is 13440, while the sum is 32.

The square root of 687542 is about 829.1815241550. The cubic root of 687542 is about 88.2605056148.

The spelling of 687542 in words is "six hundred eighty-seven thousand, five hundred forty-two".