688361 has 4 divisors (see below), whose sum is σ = 690132. Its totient is φ = 686592.

The previous prime is 688357. The next prime is 688379. The reversal of 688361 is 163886.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 163886 = 2 ⋅81943.

It can be written as a sum of positive squares in 2 ways, for example, as 570025 + 118336 = 755^2 + 344^2 .

It is a cyclic number.

It is not a de Polignac number, because 688361 - 2² = 688357 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 688361.

It is not an unprimeable number, because it can be changed into a prime (688561) 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, 20 + ... + 1173.

It is an arithmetic number, because the mean of its divisors is an integer number (172533).

2⁶⁸⁸³⁶¹ is an apocalyptic number.

It is an amenable number.

688361 is a deficient number, since it is larger than the sum of its proper divisors (1771).

688361 is a wasteful number, since it uses less digits than its factorization.

688361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1770.

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

The square root of 688361 is about 829.6752376683. The cubic root of 688361 is about 88.2955370121.

The spelling of 688361 in words is "six hundred eighty-eight thousand, three hundred sixty-one".