721168 has 40 divisors (see below), whose sum is σ = 1642752. Its totient is φ = 300288.

The previous prime is 721163. The next prime is 721169. The reversal of 721168 is 861127.

It is not an unprimeable number, because it can be changed into a prime (721163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5196 + ... + 5332.

2⁷²¹¹⁶⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 721168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (821376).

721168 is an abundant number, since it is smaller than the sum of its proper divisors (921584).

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

721168 is a wasteful number, since it uses less digits than its factorization.

721168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199 (or 193 counting only the distinct ones).

The product of its digits is 672, while the sum is 25.

The square root of 721168 is about 849.2161091265. The cubic root of 721168 is about 89.6765343099.

The spelling of 721168 in words is "seven hundred twenty-one thousand, one hundred sixty-eight".