21123122243 has 8 divisors (see below), whose sum is σ = 21692400048. Its totient is φ = 20557391904.

The previous prime is 21123122213. The next prime is 21123122249. The reversal of 21123122243 is 34222132112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21123122243 - 2¹⁰ = 21123121219 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21123122249) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 874796 + ... + 898617.

It is an arithmetic number, because the mean of its divisors is an integer number (2711550006).

Almost surely, 2^21123122243 is an apocalyptic number.

21123122243 is a deficient number, since it is larger than the sum of its proper divisors (569277805).

21123122243 is a wasteful number, since it uses less digits than its factorization.

21123122243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1773733.

The product of its digits is 1152, while the sum is 23.

Adding to 21123122243 its reverse (34222132112), we get a palindrome (55345254355).

The spelling of 21123122243 in words is "twenty-one billion, one hundred twenty-three million, one hundred twenty-two thousand, two hundred forty-three".