688722 has 16 divisors (see below), whose sum is σ = 1395840. Its totient is φ = 226512.

The previous prime is 688717. The next prime is 688729. The reversal of 688722 is 227886.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 688722.

It is not an unprimeable number, because it can be changed into a prime (688729) by changing a digit.

688722 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 7 ways as a sum of consecutive naturals, for example, 253 + ... + 1200.

It is an arithmetic number, because the mean of its divisors is an integer number (87240).

2⁶⁸⁸⁷²² is an apocalyptic number.

688722 is an abundant number, since it is smaller than the sum of its proper divisors (707118).

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

688722 is a wasteful number, since it uses less digits than its factorization.

688722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1537.

The product of its digits is 10752, while the sum is 33.

The square root of 688722 is about 829.8927641569. The cubic root of 688722 is about 88.3109693790.

The spelling of 688722 in words is "six hundred eighty-eight thousand, seven hundred twenty-two".