21143143121 has 4 divisors (see below), whose sum is σ = 21156301632. Its totient is φ = 21129984612.

The previous prime is 21143143103. The next prime is 21143143127. The reversal of 21143143121 is 12134134112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21143143121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21143143127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6576845 + ... + 6580058.

It is an arithmetic number, because the mean of its divisors is an integer number (5289075408).

Almost surely, 2^21143143121 is an apocalyptic number.

It is an amenable number.

21143143121 is a deficient number, since it is larger than the sum of its proper divisors (13158511).

21143143121 is a wasteful number, since it uses less digits than its factorization.

21143143121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13158510.

The product of its digits is 576, while the sum is 23.

Adding to 21143143121 its reverse (12134134112), we get a palindrome (33277277233).

Subtracting from 21143143121 its reverse (12134134112), we obtain a palindrome (9009009009).

The spelling of 21143143121 in words is "twenty-one billion, one hundred forty-three million, one hundred forty-three thousand, one hundred twenty-one".