21123121233 has 8 divisors (see below), whose sum is σ = 28212975328. Its totient is φ = 14057673984.

The previous prime is 21123121219. The next prime is 21123121247. The reversal of 21123121233 is 33212132112.

It is an interprime number because it is at equal distance from previous prime (21123121219) and next prime (21123121247).

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

It is not a de Polignac number, because 21123121233 - 2¹⁰ = 21123120209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21123121213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6099691 + ... + 6103152.

It is an arithmetic number, because the mean of its divisors is an integer number (3526621916).

Almost surely, 2^21123121233 is an apocalyptic number.

It is an amenable number.

21123121233 is a deficient number, since it is larger than the sum of its proper divisors (7089854095).

21123121233 is a wasteful number, since it uses less digits than its factorization.

21123121233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12203423.

The product of its digits is 432, while the sum is 21.

Adding to 21123121233 its reverse (33212132112), we get a palindrome (54335253345).

The spelling of 21123121233 in words is "twenty-one billion, one hundred twenty-three million, one hundred twenty-one thousand, two hundred thirty-three".