213120123221 has 2 divisors, whose sum is σ = 213120123222. Its totient is φ = 213120123220.

The previous prime is 213120123217. The next prime is 213120123233. The reversal of 213120123221 is 122321021312.

213120123221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 212166178225 + 953944996 = 460615^2 + 30886^2 .

It is a cyclic number.

It is not a de Polignac number, because 213120123221 - 2² = 213120123217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 213120123193 and 213120123202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213120122221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106560061610 + 106560061611.

It is an arithmetic number, because the mean of its divisors is an integer number (106560061611).

Almost surely, 2^213120123221 is an apocalyptic number.

It is an amenable number.

213120123221 is a deficient number, since it is larger than the sum of its proper divisors (1).

213120123221 is an equidigital number, since it uses as much as digits as its factorization.

213120123221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 213120123221 its reverse (122321021312), we get a palindrome (335441144533).

The spelling of 213120123221 in words is "two hundred thirteen billion, one hundred twenty million, one hundred twenty-three thousand, two hundred twenty-one".