31112209 has 2 divisors, whose sum is σ = 31112210. Its totient is φ = 31112208.

The previous prime is 31112201. The next prime is 31112281. The reversal of 31112209 is 90221113.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31047184 + 65025 = 5572^2 + 255^2 .

It is a cyclic number.

It is not a de Polignac number, because 31112209 - 2³ = 31112201 is a prime.

It is not a weakly prime, because it can be changed into another prime (31112201) 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 as a sum of consecutive naturals, namely, 15556104 + 15556105.

It is an arithmetic number, because the mean of its divisors is an integer number (15556105).

Almost surely, 2^31112209 is an apocalyptic number.

It is an amenable number.

31112209 is a deficient number, since it is larger than the sum of its proper divisors (1).

31112209 is an equidigital number, since it uses as much as digits as its factorization.

31112209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 31112209 is about 5577.8319264747. The cubic root of 31112209 is about 314.5166316232.

The spelling of 31112209 in words is "thirty-one million, one hundred twelve thousand, two hundred nine".