2121233120021 has 2 divisors, whose sum is σ = 2121233120022. Its totient is φ = 2121233120020.

The previous prime is 2121233120003. The next prime is 2121233120137. The reversal of 2121233120021 is 1200213321212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1068380640625 + 1052852479396 = 1033625^2 + 1026086^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121233120021 - 2³⁴ = 2104053250837 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2121233119975 and 2121233120002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121233120821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060616560010 + 1060616560011.

It is an arithmetic number, because the mean of its divisors is an integer number (1060616560011).

Almost surely, 2^{2121233120021} is an apocalyptic number.

It is an amenable number.

2121233120021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121233120021 is an equidigital number, since it uses as much as digits as its factorization.

2121233120021 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.

Adding to 2121233120021 its reverse (1200213321212), we get a palindrome (3321446441233).

The spelling of 2121233120021 in words is "two trillion, one hundred twenty-one billion, two hundred thirty-three million, one hundred twenty thousand, twenty-one".