10001021209 has 2 divisors, whose sum is σ = 10001021210. Its totient is φ = 10001021208.

The previous prime is 10001021131. The next prime is 10001021231. The reversal of 10001021209 is 90212010001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6092270809 + 3908750400 = 78053^2 + 62520^2 .

It is an emirp because it is prime and its reverse (90212010001) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 10001021209 - 2⁷ = 10001021081 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 10001021192 and 10001021201.

It is not a weakly prime, because it can be changed into another prime (10001021609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5000510604 + 5000510605.

It is an arithmetic number, because the mean of its divisors is an integer number (5000510605).

Almost surely, 2^10001021209 is an apocalyptic number.

It is an amenable number.

10001021209 is a deficient number, since it is larger than the sum of its proper divisors (1).

10001021209 is an equidigital number, since it uses as much as digits as its factorization.

10001021209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 16.

The spelling of 10001021209 in words is "ten billion, one million, twenty-one thousand, two hundred nine".