2001240209 has 2 divisors, whose sum is σ = 2001240210. Its totient is φ = 2001240208.

The previous prime is 2001240181. The next prime is 2001240211. The reversal of 2001240209 is 9020421002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1722250000 + 278990209 = 41500^2 + 16703^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001240209 - 2¹² = 2001236113 is a prime.

Together with 2001240211, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2001240809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000620104 + 1000620105.

It is an arithmetic number, because the mean of its divisors is an integer number (1000620105).

Almost surely, 2^2001240209 is an apocalyptic number.

It is an amenable number.

2001240209 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001240209 is an equidigital number, since it uses as much as digits as its factorization.

2001240209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 2001240209 is about 44735.2233592278. The cubic root of 2001240209 is about 1260.1814236535.

The spelling of 2001240209 in words is "two billion, one million, two hundred forty thousand, two hundred nine".