1212122120021 has 2 divisors, whose sum is σ = 1212122120022. Its totient is φ = 1212122120020.

The previous prime is 1212122119993. The next prime is 1212122120023. The reversal of 1212122120021 is 1200212212121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1047018051121 + 165104068900 = 1023239^2 + 406330^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212122120021 - 2¹⁴ = 1212122103637 is a prime.

Together with 1212122120023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1212122120023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606061060010 + 606061060011.

It is an arithmetic number, because the mean of its divisors is an integer number (606061060011).

Almost surely, 2^{1212122120021} is an apocalyptic number.

It is an amenable number.

1212122120021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212122120021 is an equidigital number, since it uses as much as digits as its factorization.

1212122120021 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 1212122120021 its reverse (1200212212121), we get a palindrome (2412334332142).

The spelling of 1212122120021 in words is "one trillion, two hundred twelve billion, one hundred twenty-two million, one hundred twenty thousand, twenty-one".