21212021121211 has 2 divisors, whose sum is σ = 21212021121212. Its totient is φ = 21212021121210.

The previous prime is 21212021121173. The next prime is 21212021121229. The reversal of 21212021121211 is 11212112021212.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21212021121211 - 2²¹ = 21212019024059 is a prime.

It is not a weakly prime, because it can be changed into another prime (21212021131211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606010560605 + 10606010560606.

It is an arithmetic number, because the mean of its divisors is an integer number (10606010560606).

Almost surely, 2^{21212021121211} is an apocalyptic number.

21212021121211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212021121211 is an equidigital number, since it uses as much as digits as its factorization.

21212021121211 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21212021121211 its reverse (11212112021212), we get a palindrome (32424133142423).

Subtracting from 21212021121211 its reverse (11212112021212), we obtain a palindrome (9999909099999).

The spelling of 21212021121211 in words is "twenty-one trillion, two hundred twelve billion, twenty-one million, one hundred twenty-one thousand, two hundred eleven".