687540 has 48 divisors (see below), whose sum is σ = 2201472. Its totient is φ = 157056.

The previous prime is 687523. The next prime is 687541. The reversal of 687540 is 45786.

It is a happy number.

It is a super-2 number, since 2×687540² = 945422503200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 687498 and 687507.

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 687540.

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

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 399 + ... + 1238.

It is an arithmetic number, because the mean of its divisors is an integer number (45864).

2⁶⁸⁷⁵⁴⁰ is an apocalyptic number.

687540 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

687540 is an abundant number, since it is smaller than the sum of its proper divisors (1513932).

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

687540 is a wasteful number, since it uses less digits than its factorization.

687540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1656 (or 1654 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 687540 is about 829.1803181456. The cubic root of 687540 is about 88.2604200340.

The spelling of 687540 in words is "six hundred eighty-seven thousand, five hundred forty".