2001111121 has 2 divisors, whose sum is σ = 2001111122. Its totient is φ = 2001111120.

The previous prime is 2001111107. The next prime is 2001111131. The reversal of 2001111121 is 1211111002.

It is an a-pointer prime, because the next prime (2001111131) can be obtained adding 2001111121 to its sum of digits (10).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1566972225 + 434138896 = 39585^2 + 20836^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001111121 - 2¹⁷ = 2000980049 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2001111098 and 2001111107.

It is not a weakly prime, because it can be changed into another prime (2001111131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000555560 + 1000555561.

It is an arithmetic number, because the mean of its divisors is an integer number (1000555561).

Almost surely, 2^2001111121 is an apocalyptic number.

It is an amenable number.

2001111121 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001111121 is an equidigital number, since it uses as much as digits as its factorization.

2001111121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4, while the sum is 10.

The square root of 2001111121 is about 44733.7805355192. The cubic root of 2001111121 is about 1260.1543274897.

Adding to 2001111121 its reverse (1211111002), we get a palindrome (3212222123).

The spelling of 2001111121 in words is "two billion, one million, one hundred eleven thousand, one hundred twenty-one".