201131209 has 2 divisors, whose sum is σ = 201131210. Its totient is φ = 201131208.

The previous prime is 201131201. The next prime is 201131219. The reversal of 201131209 is 902131102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 163123984 + 38007225 = 12772^2 + 6165^2 .

It is a cyclic number.

It is not a de Polignac number, because 201131209 - 2³ = 201131201 is a prime.

It is not a weakly prime, because it can be changed into another prime (201131201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100565604 + 100565605.

It is an arithmetic number, because the mean of its divisors is an integer number (100565605).

Almost surely, 2^201131209 is an apocalyptic number.

It is an amenable number.

201131209 is a deficient number, since it is larger than the sum of its proper divisors (1).

201131209 is an equidigital number, since it uses as much as digits as its factorization.

201131209 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 201131209 is about 14182.0735084825. The cubic root of 201131209 is about 585.9040338371.

The spelling of 201131209 in words is "two hundred one million, one hundred thirty-one thousand, two hundred nine".