531440 has 80 divisors (see below), whose sum is σ = 1541568. Its totient is φ = 165888.

The previous prime is 531383. The next prime is 531457. The reversal of 531440 is 44135.

531440 is nontrivially palindromic in base 3 and base 9.

It is a Cunningham number, because it is equal to 3¹²-1.

It is a tau number, because it is divible by the number of its divisors (80).

It is an Ulam number.

531440 is a nontrivial repdigit in base 3 and base 9.

It is a plaindrome in base 3 and base 9.

It is a nialpdrome in base 3, base 9 and base 14.

It is a zygodrome in base 3 and base 9.

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 531440.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7244 + ... + 7316.

531440 is a Friedman number, since it can be written as ((5+4)*3)^4-1-0, using all its digits and the basic arithmetic operations.

2⁵³¹⁴⁴⁰ 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 531440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (770784).

531440 is an abundant number, since it is smaller than the sum of its proper divisors (1010128).

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

531440 is a wasteful number, since it uses less digits than its factorization.

531440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106 (or 100 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 531440 is about 728.9993141286. Note that the first 3 decimals coincide. The cubic root of 531440 is about 80.9999491947. Note that the first 4 decimals are identical.

Adding to 531440 its reverse (44135), we get a palindrome (575575).

The spelling of 531440 in words is "five hundred thirty-one thousand, four hundred forty".