103131209 has 2 divisors, whose sum is σ = 103131210. Its totient is φ = 103131208.

The previous prime is 103131181. The next prime is 103131211. The reversal of 103131209 is 902131301.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 94633984 + 8497225 = 9728^2 + 2915^2 .

It is a cyclic number.

It is not a de Polignac number, because 103131209 - 2¹² = 103127113 is a prime.

Together with 103131211, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (103131229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51565604 + 51565605.

It is an arithmetic number, because the mean of its divisors is an integer number (51565605).

Almost surely, 2^103131209 is an apocalyptic number.

It is an amenable number.

103131209 is a deficient number, since it is larger than the sum of its proper divisors (1).

103131209 is an equidigital number, since it uses as much as digits as its factorization.

103131209 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 103131209 is about 10155.3537112205. The cubic root of 103131209 is about 468.9537751294.

The spelling of 103131209 in words is "one hundred three million, one hundred thirty-one thousand, two hundred nine".