31312243 has 2 divisors, whose sum is σ = 31312244. Its totient is φ = 31312242.

The previous prime is 31312219. The next prime is 31312273. The reversal of 31312243 is 34221313.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31312243 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31312243.

It is not a weakly prime, because it can be changed into another prime (31312273) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15656121 + 15656122.

It is an arithmetic number, because the mean of its divisors is an integer number (15656122).

Almost surely, 2^31312243 is an apocalyptic number.

31312243 is a deficient number, since it is larger than the sum of its proper divisors (1).

31312243 is an equidigital number, since it uses as much as digits as its factorization.

31312243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 19.

The square root of 31312243 is about 5595.7343575263. The cubic root of 31312243 is about 315.1892471606.

Adding to 31312243 its reverse (34221313), we get a palindrome (65533556).

The spelling of 31312243 in words is "thirty-one million, three hundred twelve thousand, two hundred forty-three".