21002222123 has 2 divisors, whose sum is σ = 21002222124. Its totient is φ = 21002222122.

The previous prime is 21002222099. The next prime is 21002222141. The reversal of 21002222123 is 32122220012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21002222123 - 2¹⁰ = 21002221099 is a prime.

It is not a weakly prime, because it can be changed into another prime (21002222183) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501111061 + 10501111062.

It is an arithmetic number, because the mean of its divisors is an integer number (10501111062).

Almost surely, 2^21002222123 is an apocalyptic number.

21002222123 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002222123 is an equidigital number, since it uses as much as digits as its factorization.

21002222123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 17.

Adding to 21002222123 its reverse (32122220012), we get a palindrome (53124442135).

The spelling of 21002222123 in words is "twenty-one billion, two million, two hundred twenty-two thousand, one hundred twenty-three".