21243112133 has 16 divisors (see below), whose sum is σ = 22416240000. Its totient is φ = 20091551040.

The previous prime is 21243112069. The next prime is 21243112139. The reversal of 21243112133 is 33121134212.

It is a cyclic number.

It is not a de Polignac number, because 21243112133 - 2⁶ = 21243112069 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21243112099 and 21243112108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21243112139) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1242503 + ... + 1259483.

It is an arithmetic number, because the mean of its divisors is an integer number (1401015000).

Almost surely, 2^21243112133 is an apocalyptic number.

21243112133 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21243112133 is a deficient number, since it is larger than the sum of its proper divisors (1173127867).

21243112133 is a wasteful number, since it uses less digits than its factorization.

21243112133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17612.

The product of its digits is 864, while the sum is 23.

Adding to 21243112133 its reverse (33121134212), we get a palindrome (54364246345).

The spelling of 21243112133 in words is "twenty-one billion, two hundred forty-three million, one hundred twelve thousand, one hundred thirty-three".