687613 has 4 divisors (see below), whose sum is σ = 703648. Its totient is φ = 671580.

The previous prime is 687593. The next prime is 687623. The reversal of 687613 is 316786.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 316786 = 2 ⋅158393.

It is a cyclic number.

It is not a de Polignac number, because 687613 - 2⁵ = 687581 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687623) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7953 + ... + 8038.

It is an arithmetic number, because the mean of its divisors is an integer number (175912).

2⁶⁸⁷⁶¹³ is an apocalyptic number.

It is an amenable number.

687613 is a deficient number, since it is larger than the sum of its proper divisors (16035).

687613 is a wasteful number, since it uses less digits than its factorization.

687613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16034.

The product of its digits is 6048, while the sum is 31.

The square root of 687613 is about 829.2243363530. The cubic root of 687613 is about 88.2635436257.

It can be divided in two parts, 6876 and 13, that added together give a square (6889 = 83²).

The spelling of 687613 in words is "six hundred eighty-seven thousand, six hundred thirteen".