21112212122123 has 4 divisors (see below), whose sum is σ = 21238632554160. Its totient is φ = 20985791690088.

The previous prime is 21112212122077. The next prime is 21112212122179. The reversal of 21112212122123 is 32122121221112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21112212122123 - 2¹⁶ = 21112212056587 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21112212422123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63210215768 + ... + 63210216101.

It is an arithmetic number, because the mean of its divisors is an integer number (5309658138540).

Almost surely, 2^{21112212122123} is an apocalyptic number.

21112212122123 is a deficient number, since it is larger than the sum of its proper divisors (126420432037).

21112212122123 is a wasteful number, since it uses less digits than its factorization.

21112212122123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126420432036.

The product of its digits is 384, while the sum is 23.

Adding to 21112212122123 its reverse (32122121221112), we get a palindrome (53234333343235).

The spelling of 21112212122123 in words is "twenty-one trillion, one hundred twelve billion, two hundred twelve million, one hundred twenty-two thousand, one hundred twenty-three".