1021001000209 has 2 divisors, whose sum is σ = 1021001000210. Its totient is φ = 1021001000208.

The previous prime is 1021001000203. The next prime is 1021001000237. The reversal of 1021001000209 is 9020001001201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 961841140225 + 59159859984 = 980735^2 + 243228^2 .

It is an emirp because it is prime and its reverse (9020001001201) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1021001000209 - 2¹¹ = 1021000998161 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1021001000192 and 1021001000201.

It is not a weakly prime, because it can be changed into another prime (1021001000203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510500500104 + 510500500105.

It is an arithmetic number, because the mean of its divisors is an integer number (510500500105).

Almost surely, 2^{1021001000209} is an apocalyptic number.

It is an amenable number.

1021001000209 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021001000209 is an equidigital number, since it uses as much as digits as its factorization.

1021001000209 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 16.

The spelling of 1021001000209 in words is "one trillion, twenty-one billion, one million, two hundred nine", and thus it is an aban number.