31043440 has 40 divisors (see below), whose sum is σ = 73410480. Its totient is φ = 12205056.

The previous prime is 31043417. The next prime is 31043443. The reversal of 31043440 is 4434013.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31043443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1432 + ... + 8008.

It is an arithmetic number, because the mean of its divisors is an integer number (1835262).

Almost surely, 2^31043440 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 31043440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36705240).

31043440 is an abundant number, since it is smaller than the sum of its proper divisors (42367040).

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

31043440 is a wasteful number, since it uses less digits than its factorization.

31043440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6649 (or 6643 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 31043440 is about 5571.6640243288. The cubic root of 31043440 is about 314.2847296309.

Adding to 31043440 its reverse (4434013), we get a palindrome (35477453).

The spelling of 31043440 in words is "thirty-one million, forty-three thousand, four hundred forty".