321440 has 72 divisors (see below), whose sum is σ = 904932. Its totient is φ = 107520.

The previous prime is 321427. The next prime is 321443. The reversal of 321440 is 44123.

321440 = T₂₉ + T₃₀ + ... + T₁₂₄.

321440 is nontrivially palindromic in base 9.

It can be written as a sum of positive squares in 2 ways, for example, as 283024 + 38416 = 532^2 + 196^2 .

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a nialpdrome in base 14.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 321440.

It is not an unprimeable number, because it can be changed into a prime (321443) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7820 + ... + 7860.

2³²¹⁴⁴⁰ 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 321440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (452466).

321440 is an abundant number, since it is smaller than the sum of its proper divisors (583492).

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

321440 is a wasteful number, since it uses less digits than its factorization.

321440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70 (or 55 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 321440 is about 566.9567884769. The cubic root of 321440 is about 68.5014829096.

Adding to 321440 its reverse (44123), we get a palindrome (365563).

The spelling of 321440 in words is "three hundred twenty-one thousand, four hundred forty", and thus it is an iban number.