31125239 has 2 divisors, whose sum is σ = 31125240. Its totient is φ = 31125238.

The previous prime is 31125221. The next prime is 31125247. The reversal of 31125239 is 93252113.

It is a strong prime.

It is an emirp because it is prime and its reverse (93252113) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31125239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (36125239) 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 as a sum of consecutive naturals, namely, 15562619 + 15562620.

It is an arithmetic number, because the mean of its divisors is an integer number (15562620).

Almost surely, 2^31125239 is an apocalyptic number.

31125239 is a deficient number, since it is larger than the sum of its proper divisors (1).

31125239 is an equidigital number, since it uses as much as digits as its factorization.

31125239 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1620, while the sum is 26.

The square root of 31125239 is about 5578.9998207564. Note that the first 3 decimals coincide. The cubic root of 31125239 is about 314.5605327139.

The spelling of 31125239 in words is "thirty-one million, one hundred twenty-five thousand, two hundred thirty-nine".