201020009 has 2 divisors, whose sum is σ = 201020010. Its totient is φ = 201020008.

The previous prime is 201019999. The next prime is 201020011. The reversal of 201020009 is 900020102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 153685609 + 47334400 = 12397^2 + 6880^2 .

It is a cyclic number.

It is not a de Polignac number, because 201020009 - 2²⁰ = 199971433 is a prime.

Together with 201020011, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 201019975 and 201020002.

It is not a weakly prime, because it can be changed into another prime (201026009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100510004 + 100510005.

It is an arithmetic number, because the mean of its divisors is an integer number (100510005).

Almost surely, 2^201020009 is an apocalyptic number.

It is an amenable number.

201020009 is a deficient number, since it is larger than the sum of its proper divisors (1).

201020009 is an equidigital number, since it uses as much as digits as its factorization.

201020009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36, while the sum is 14.

The square root of 201020009 is about 14178.1525242184. The cubic root of 201020009 is about 585.7960371060.

The spelling of 201020009 in words is "two hundred one million, twenty thousand, nine".