120211201221821 has 2 divisors, whose sum is σ = 120211201221822. Its totient is φ = 120211201221820.

The previous prime is 120211201221799. The next prime is 120211201221823. The reversal of 120211201221821 is 128122102112021.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 110225032413721 + 9986168808100 = 10498811^2 + 3160090^2 .

It is a cyclic number.

It is not a de Polignac number, because 120211201221821 - 2¹⁸ = 120211200959677 is a prime.

Together with 120211201221823, 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 (120211201221823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60105600610910 + 60105600610911.

It is an arithmetic number, because the mean of its divisors is an integer number (60105600610911).

Almost surely, 2^{120211201221821} is an apocalyptic number.

It is an amenable number.

120211201221821 is a deficient number, since it is larger than the sum of its proper divisors (1).

120211201221821 is an equidigital number, since it uses as much as digits as its factorization.

120211201221821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 512, while the sum is 26.

Adding to 120211201221821 its reverse (128122102112021), we get a palindrome (248333303333842).

The spelling of 120211201221821 in words is "one hundred twenty trillion, two hundred eleven billion, two hundred one million, two hundred twenty-one thousand, eight hundred twenty-one".