21211222021211 has 2 divisors, whose sum is σ = 21211222021212. Its totient is φ = 21211222021210.

The previous prime is 21211222021141. The next prime is 21211222021219. The reversal of 21211222021211 is 11212022211212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21211222021211 - 2¹⁸ = 21211221759067 is a prime.

It is not a weakly prime, because it can be changed into another prime (21211222021219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605611010605 + 10605611010606.

It is an arithmetic number, because the mean of its divisors is an integer number (10605611010606).

Almost surely, 2^{21211222021211} is an apocalyptic number.

21211222021211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211222021211 is an equidigital number, since it uses as much as digits as its factorization.

21211222021211 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 21211222021211 its reverse (11212022211212), we get a palindrome (32423244232423).

The spelling of 21211222021211 in words is "twenty-one trillion, two hundred eleven billion, two hundred twenty-two million, twenty-one thousand, two hundred eleven".