2001211111021 has 2 divisors, whose sum is σ = 2001211111022. Its totient is φ = 2001211111020.

The previous prime is 2001211111013. The next prime is 2001211111073. The reversal of 2001211111021 is 1201111121002.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1995964281796 + 5246829225 = 1412786^2 + 72435^2 .

It is a cyclic number.

It is not a de Polignac number, because 2001211111021 - 2³ = 2001211111013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2001211110992 and 2001211111010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2001211118021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000605555510 + 1000605555511.

It is an arithmetic number, because the mean of its divisors is an integer number (1000605555511).

Almost surely, 2^{2001211111021} is an apocalyptic number.

It is an amenable number.

2001211111021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2001211111021 is an equidigital number, since it uses as much as digits as its factorization.

2001211111021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 2001211111021 its reverse (1201111121002), we get a palindrome (3202322232023).

The spelling of 2001211111021 in words is "two trillion, one billion, two hundred eleven million, one hundred eleven thousand, twenty-one".