321121440 has 144 divisors (see below), whose sum is σ = 1101227400. Its totient is φ = 85211136.

The previous prime is 321121417. The next prime is 321121441. The reversal of 321121440 is 44121123.

321121440 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 191434896 + 129686544 = 13836^2 + 11388^2 .

It is a tau number, because it is divible by the number of its divisors (144).

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

It is not an unprimeable number, because it can be changed into a prime (321121441) 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 23 ways as a sum of consecutive naturals, for example, 386946 + ... + 387774.

Almost surely, 2^321121440 is an apocalyptic number.

321121440 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 321121440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (550613700).

321121440 is an abundant number, since it is smaller than the sum of its proper divisors (780105960).

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

321121440 is a wasteful number, since it uses less digits than its factorization.

321121440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1119 (or 1108 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 321121440 is about 17919.8616066085. The cubic root of 321121440 is about 684.7884618620.

Adding to 321121440 its reverse (44121123), we get a palindrome (365242563).

The spelling of 321121440 in words is "three hundred twenty-one million, one hundred twenty-one thousand, four hundred forty".