31440323 has 4 divisors (see below), whose sum is σ = 31452720. Its totient is φ = 31427928.

The previous prime is 31440257. The next prime is 31440337. The reversal of 31440323 is 32304413.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 32304413 = 859 ⋅37607.

It is a cyclic number.

It is not a de Polignac number, because 31440323 - 2⁸ = 31440067 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31440295 and 31440304.

It is not an unprimeable number, because it can be changed into a prime (31440223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 863 + ... + 7976.

It is an arithmetic number, because the mean of its divisors is an integer number (7863180).

Almost surely, 2^31440323 is an apocalyptic number.

31440323 is a deficient number, since it is larger than the sum of its proper divisors (12397).

31440323 is an equidigital number, since it uses as much as digits as its factorization.

31440323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12396.

The product of its (nonzero) digits is 864, while the sum is 20.

The square root of 31440323 is about 5607.1671100476. The cubic root of 31440323 is about 315.6184139135.

Adding to 31440323 its reverse (32304413), we get a palindrome (63744736).

The spelling of 31440323 in words is "thirty-one million, four hundred forty thousand, three hundred twenty-three".