2011021120021 has 2 divisors, whose sum is σ = 2011021120022. Its totient is φ = 2011021120020.

The previous prime is 2011021120019. The next prime is 2011021120037. The reversal of 2011021120021 is 1200211201102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1215481995121 + 795539124900 = 1102489^2 + 891930^2 .

It is a cyclic number.

It is not a de Polignac number, because 2011021120021 - 2¹ = 2011021120019 is a prime.

Together with 2011021120019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 2011021119983 and 2011021120010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2011021120091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1005510560010 + 1005510560011.

It is an arithmetic number, because the mean of its divisors is an integer number (1005510560011).

Almost surely, 2^{2011021120021} is an apocalyptic number.

It is an amenable number.

2011021120021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2011021120021 is an equidigital number, since it uses as much as digits as its factorization.

2011021120021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 2011021120021 its reverse (1200211201102), we get a palindrome (3211232321123).

The spelling of 2011021120021 in words is "two trillion, eleven billion, twenty-one million, one hundred twenty thousand, twenty-one".