2001311209 has 2 divisors, whose sum is σ = 2001311210. Its totient is φ = 2001311208.

The previous prime is 2001311149. The next prime is 2001311243. The reversal of 2001311209 is 9021131002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1999878400 + 1432809 = 44720^2 + 1197^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001311209 - 2¹⁵ = 2001278441 is a prime.

It is not a weakly prime, because it can be changed into another prime (2001314209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000655604 + 1000655605.

It is an arithmetic number, because the mean of its divisors is an integer number (1000655605).

Almost surely, 2^2001311209 is an apocalyptic number.

It is an amenable number.

2001311209 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001311209 is an equidigital number, since it uses as much as digits as its factorization.

2001311209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 2001311209 is about 44736.0169103151. The cubic root of 2001311209 is about 1260.1963263828.

The spelling of 2001311209 in words is "two billion, one million, three hundred eleven thousand, two hundred nine".