2001211181 has 2 divisors, whose sum is σ = 2001211182. Its totient is φ = 2001211180.

The previous prime is 2001211159. The next prime is 2001211237. The reversal of 2001211181 is 1811121002.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1981051081 + 20160100 = 44509^2 + 4490^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2001211181 is a prime.

It is a super-2 number, since 2×2001211181² = 8009692381918829522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2001211111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000605590 + 1000605591.

It is an arithmetic number, because the mean of its divisors is an integer number (1000605591).

Almost surely, 2^2001211181 is an apocalyptic number.

It is an amenable number.

2001211181 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001211181 is an equidigital number, since it uses as much as digits as its factorization.

2001211181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 17.

The square root of 2001211181 is about 44734.8989157235. The cubic root of 2001211181 is about 1260.1753306446.

Adding to 2001211181 its reverse (1811121002), we get a palindrome (3812332183).

The spelling of 2001211181 in words is "two billion, one million, two hundred eleven thousand, one hundred eighty-one".