31230440 has 32 divisors (see below), whose sum is σ = 70730280. Its totient is φ = 12410112.

The previous prime is 31230439. The next prime is 31230449. The reversal of 31230440 is 4403213.

31230440 = 783² + 784² + ... + 830².

It can be written as a sum of positive squares in 4 ways, for example, as 24186724 + 7043716 = 4918^2 + 2654^2 .

It is not an unprimeable number, because it can be changed into a prime (31230449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3794 + ... + 8766.

Almost surely, 2^31230440 is an apocalyptic number.

It is an amenable number.

31230440 is an abundant number, since it is smaller than the sum of its proper divisors (39499840).

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

31230440 is a wasteful number, since it uses less digits than its factorization.

31230440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5141 (or 5137 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 31230440 is about 5588.4201703165. The cubic root of 31230440 is about 314.9145312757.

Adding to 31230440 its reverse (4403213), we get a palindrome (35633653).

The spelling of 31230440 in words is "thirty-one million, two hundred thirty thousand, four hundred forty".