2121021221021 has 2 divisors, whose sum is σ = 2121021221022. Its totient is φ = 2121021221020.

The previous prime is 2121021221003. The next prime is 2121021221063. The reversal of 2121021221021 is 1201221201212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1547563368121 + 573457852900 = 1244011^2 + 757270^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121021221021 - 2¹⁰ = 2121021219997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121021271021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060510610510 + 1060510610511.

It is an arithmetic number, because the mean of its divisors is an integer number (1060510610511).

Almost surely, 2^{2121021221021} is an apocalyptic number.

It is an amenable number.

2121021221021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121021221021 is an equidigital number, since it uses as much as digits as its factorization.

2121021221021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 2121021221021 its reverse (1201221201212), we get a palindrome (3322242422233).

The spelling of 2121021221021 in words is "two trillion, one hundred twenty-one billion, twenty-one million, two hundred twenty-one thousand, twenty-one".