21212222123 has 2 divisors, whose sum is σ = 21212222124. Its totient is φ = 21212222122.

The previous prime is 21212222093. The next prime is 21212222149. The reversal of 21212222123 is 32122221212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21212222123 - 2⁸ = 21212221867 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21212222095 and 21212222104.

It is not a weakly prime, because it can be changed into another prime (21212222153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606111061 + 10606111062.

It is an arithmetic number, because the mean of its divisors is an integer number (10606111062).

Almost surely, 2^21212222123 is an apocalyptic number.

21212222123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212222123 is an equidigital number, since it uses as much as digits as its factorization.

21212222123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 384, while the sum is 20.

Adding to 21212222123 its reverse (32122221212), we get a palindrome (53334443335).

The spelling of 21212222123 in words is "twenty-one billion, two hundred twelve million, two hundred twenty-two thousand, one hundred twenty-three".