688613 has 4 divisors (see below), whose sum is σ = 692640. Its totient is φ = 684588.

The previous prime is 688591. The next prime is 688621. The reversal of 688613 is 316886.

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: 316886 = 2 ⋅158443.

It is a cyclic number.

It is not a de Polignac number, because 688613 - 2⁸ = 688357 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 688613.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688013) 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, 1745 + ... + 2102.

It is an arithmetic number, because the mean of its divisors is an integer number (173160).

2⁶⁸⁸⁶¹³ is an apocalyptic number.

It is an amenable number.

688613 is a deficient number, since it is larger than the sum of its proper divisors (4027).

688613 is a wasteful number, since it uses less digits than its factorization.

688613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4026.

The product of its digits is 6912, while the sum is 32.

The square root of 688613 is about 829.8270904231. The cubic root of 688613 is about 88.3063103131.

The spelling of 688613 in words is "six hundred eighty-eight thousand, six hundred thirteen".