320721120 has 288 divisors, whose sum is σ = 1160726112. Its totient is φ = 83607552.

The previous prime is 320721061. The next prime is 320721127. The reversal of 320721120 is 21127023.

It is a tau number, because it is divible by the number of its divisors (288).

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

It is a junction number, because it is equal to n+sod(n) for n = 320721093 and 320721102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (320721127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2838184 + ... + 2838296.

It is an arithmetic number, because the mean of its divisors is an integer number (4030299).

Almost surely, 2^320721120 is an apocalyptic number.

320721120 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 320721120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (580363056).

320721120 is an abundant number, since it is smaller than the sum of its proper divisors (840004992).

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

320721120 is a wasteful number, since it uses less digits than its factorization.

320721120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216 (or 196 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 320721120 is about 17908.6883941845. The cubic root of 320721120 is about 684.5037839834.

Adding to 320721120 its reverse (21127023), we get a palindrome (341848143).

The spelling of 320721120 in words is "three hundred twenty million, seven hundred twenty-one thousand, one hundred twenty".