31103309 has 2 divisors, whose sum is σ = 31103310. Its totient is φ = 31103308.

The previous prime is 31103279. The next prime is 31103311. The reversal of 31103309 is 90330113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15721225 + 15382084 = 3965^2 + 3922^2 .

It is an emirp because it is prime and its reverse (90330113) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31103309 - 2⁸ = 31103053 is a prime.

Together with 31103311, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31103909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15551654 + 15551655.

It is an arithmetic number, because the mean of its divisors is an integer number (15551655).

Almost surely, 2^31103309 is an apocalyptic number.

It is an amenable number.

31103309 is a deficient number, since it is larger than the sum of its proper divisors (1).

31103309 is an equidigital number, since it uses as much as digits as its factorization.

31103309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 243, while the sum is 20.

The square root of 31103309 is about 5577.0340683915. The cubic root of 31103309 is about 314.4866384140.

The spelling of 31103309 in words is "thirty-one million, one hundred three thousand, three hundred nine".