21121112122211 has 2 divisors, whose sum is σ = 21121112122212. Its totient is φ = 21121112122210.

The previous prime is 21121112122207. The next prime is 21121112122259. The reversal of 21121112122211 is 11222121112112.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21121112122211 - 2² = 21121112122207 is a prime.

It is a super-2 number, since 2×21121112122211² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21121112152211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560556061105 + 10560556061106.

It is an arithmetic number, because the mean of its divisors is an integer number (10560556061106).

Almost surely, 2^{21121112122211} is an apocalyptic number.

21121112122211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21121112122211 is an equidigital number, since it uses as much as digits as its factorization.

21121112122211 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 64, while the sum is 20.

Adding to 21121112122211 its reverse (11222121112112), we get a palindrome (32343233234323).

The spelling of 21121112122211 in words is "twenty-one trillion, one hundred twenty-one billion, one hundred twelve million, one hundred twenty-two thousand, two hundred eleven".