31287243 has 16 divisors (see below), whose sum is σ = 47290880. Its totient is φ = 18239904.

The previous prime is 31287233. The next prime is 31287257. The reversal of 31287243 is 34278213.

It is not a de Polignac number, because 31287243 - 2¹⁴ = 31270859 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is the 5594-th Hogben number.

It is a self number, because there is not a number n which added to its sum of digits gives 31287243.

It is not an unprimeable number, because it can be changed into a prime (31287203) by changing a digit.

It is a nontrivial repunit in base 5593.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20371 + ... + 21852.

It is an arithmetic number, because the mean of its divisors is an integer number (2955680).

Almost surely, 2^31287243 is an apocalyptic number.

31287243 is a deficient number, since it is larger than the sum of its proper divisors (16003637).

31287243 is a wasteful number, since it uses less digits than its factorization.

31287243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42258.

The product of its digits is 8064, while the sum is 30.

The square root of 31287243 is about 5593.5000670421. The cubic root of 31287243 is about 315.1053414373.

The spelling of 31287243 in words is "thirty-one million, two hundred eighty-seven thousand, two hundred forty-three".