688422 has 32 divisors (see below), whose sum is σ = 1619712. Its totient is φ = 190944.

The previous prime is 688411. The next prime is 688423. The reversal of 688422 is 224886.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 688422.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688423) by changing a digit.

688422 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1333 + ... + 1775.

It is an arithmetic number, because the mean of its divisors is an integer number (50616).

2⁶⁸⁸⁴²² is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 688422, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (809856).

688422 is an abundant number, since it is smaller than the sum of its proper divisors (931290).

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

688422 is a wasteful number, since it uses less digits than its factorization.

688422 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 492.

The product of its digits is 6144, while the sum is 30.

The square root of 688422 is about 829.7119982259. The cubic root of 688422 is about 88.2981450762.

The spelling of 688422 in words is "six hundred eighty-eight thousand, four hundred twenty-two".