31123109 has 2 divisors, whose sum is σ = 31123110. Its totient is φ = 31123108.

The previous prime is 31123093. The next prime is 31123123. The reversal of 31123109 is 90132113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31114084 + 9025 = 5578^2 + 95^2 .

It is a cyclic number.

It is not a de Polignac number, because 31123109 - 2⁴ = 31123093 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31123139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15561554 + 15561555.

It is an arithmetic number, because the mean of its divisors is an integer number (15561555).

Almost surely, 2^31123109 is an apocalyptic number.

It is an amenable number.

31123109 is a deficient number, since it is larger than the sum of its proper divisors (1).

31123109 is an equidigital number, since it uses as much as digits as its factorization.

31123109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 162, while the sum is 20.

The square root of 31123109 is about 5578.8089230588. The cubic root of 31123109 is about 314.5533570879.

The spelling of 31123109 in words is "thirty-one million, one hundred twenty-three thousand, one hundred nine".