31109009 has 2 divisors, whose sum is σ = 31109010. Its totient is φ = 31109008.

The previous prime is 31108993. The next prime is 31109011. The reversal of 31109009 is 90090113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17808400 + 13300609 = 4220^2 + 3647^2 .

It is a cyclic number.

It is not a de Polignac number, because 31109009 - 2⁴ = 31108993 is a prime.

It is a Sophie Germain prime.

Together with 31109011, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (31109209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15554504 + 15554505.

It is an arithmetic number, because the mean of its divisors is an integer number (15554505).

Almost surely, 2^31109009 is an apocalyptic number.

It is an amenable number.

31109009 is a deficient number, since it is larger than the sum of its proper divisors (1).

31109009 is an equidigital number, since it uses as much as digits as its factorization.

31109009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 243, while the sum is 23.

The square root of 31109009 is about 5577.5450692935. The cubic root of 31109009 is about 314.5058482066.

The spelling of 31109009 in words is "thirty-one million, one hundred nine thousand, nine".