721116 has 48 divisors (see below), whose sum is σ = 2042880. Its totient is φ = 218160.

The previous prime is 721111. The next prime is 721117. The reversal of 721116 is 611127.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721111) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 885 + ... + 1491.

It is an arithmetic number, because the mean of its divisors is an integer number (42560).

2⁷²¹¹¹⁶ 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 721116, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1021440).

721116 is an abundant number, since it is smaller than the sum of its proper divisors (1321764).

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

721116 is a wasteful number, since it uses less digits than its factorization.

721116 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 631 (or 623 counting only the distinct ones).

The product of its digits is 84, while the sum is 18.

The square root of 721116 is about 849.1854921041. The cubic root of 721116 is about 89.6743788751.

It can be divided in two parts, 7211 and 16, that added together give a palindrome (7227).

The spelling of 721116 in words is "seven hundred twenty-one thousand, one hundred sixteen".