21211221112129 has 2 divisors, whose sum is σ = 21211221112130. Its totient is φ = 21211221112128.

The previous prime is 21211221112073. The next prime is 21211221112177. The reversal of 21211221112129 is 92121112211212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12918992490000 + 8292228622129 = 3594300^2 + 2879623^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211221112129 - 2⁹ = 21211221111617 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21211221112097 and 21211221112106.

It is not a weakly prime, because it can be changed into another prime (21211221110129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605610556064 + 10605610556065.

It is an arithmetic number, because the mean of its divisors is an integer number (10605610556065).

Almost surely, 2^{21211221112129} is an apocalyptic number.

It is an amenable number.

21211221112129 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211221112129 is an equidigital number, since it uses as much as digits as its factorization.

21211221112129 is an evil number, because the sum of its binary digits is even.

The product of its digits is 576, while the sum is 28.

The spelling of 21211221112129 in words is "twenty-one trillion, two hundred eleven billion, two hundred twenty-one million, one hundred twelve thousand, one hundred twenty-nine".