31440443 has 4 divisors (see below), whose sum is σ = 31871208. Its totient is φ = 31009680.

The previous prime is 31440427. The next prime is 31440449. The reversal of 31440443 is 34404413.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31440443 - 2⁴ = 31440427 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31440449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 215273 + ... + 215418.

It is an arithmetic number, because the mean of its divisors is an integer number (7967802).

Almost surely, 2^31440443 is an apocalyptic number.

31440443 is a deficient number, since it is larger than the sum of its proper divisors (430765).

31440443 is an equidigital number, since it uses as much as digits as its factorization.

31440443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430764.

The product of its (nonzero) digits is 2304, while the sum is 23.

The square root of 31440443 is about 5607.1778106281. The cubic root of 31440443 is about 315.6188154590.

Adding to 31440443 its reverse (34404413), we get a palindrome (65844856).

The spelling of 31440443 in words is "thirty-one million, four hundred forty thousand, four hundred forty-three".