31244209 has 2 divisors, whose sum is σ = 31244210. Its totient is φ = 31244208.

The previous prime is 31244203. The next prime is 31244221. The reversal of 31244209 is 90244213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31192225 + 51984 = 5585^2 + 228^2 .

It is a cyclic number.

It is not a de Polignac number, because 31244209 - 2²³ = 22855601 is a prime.

It is not a weakly prime, because it can be changed into another prime (31244203) by changing a digit.

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 as a sum of consecutive naturals, namely, 15622104 + 15622105.

It is an arithmetic number, because the mean of its divisors is an integer number (15622105).

Almost surely, 2^31244209 is an apocalyptic number.

It is an amenable number.

31244209 is a deficient number, since it is larger than the sum of its proper divisors (1).

31244209 is an equidigital number, since it uses as much as digits as its factorization.

31244209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 31244209 is about 5589.6519569648. The cubic root of 31244209 is about 314.9608047310.

It can be divided in two parts, 312 and 44209, that added together give a square (44521 = 211²).

The spelling of 31244209 in words is "thirty-one million, two hundred forty-four thousand, two hundred nine".