686172 has 24 divisors (see below), whose sum is σ = 1614592. Its totient is φ = 226800.

The previous prime is 686149. The next prime is 686173. The reversal of 686172 is 271686.

It is a happy number.

686172 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 686172.

It is not an unprimeable number, because it can be changed into a prime (686173) by changing a digit.

686172 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2397 + ... + 2667.

2⁶⁸⁶¹⁷² is an apocalyptic number.

It is an amenable number.

686172 is an abundant number, since it is smaller than the sum of its proper divisors (928420).

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

686172 is a wasteful number, since it uses less digits than its factorization.

686172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 489 (or 487 counting only the distinct ones).

The product of its digits is 4032, while the sum is 30.

The square root of 686172 is about 828.3549963633. The cubic root of 686172 is about 88.2018438434.

It can be divided in two parts, 686 and 172, that added together give a palindrome (858).

The spelling of 686172 in words is "six hundred eighty-six thousand, one hundred seventy-two".