21343121323 has 4 divisors (see below), whose sum is σ = 21343422240. Its totient is φ = 21342820408.

The previous prime is 21343121309. The next prime is 21343121341. The reversal of 21343121323 is 32312134312.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21343121323 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21343121383) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21261 + ... + 207697.

It is an arithmetic number, because the mean of its divisors is an integer number (5335855560).

Almost surely, 2^21343121323 is an apocalyptic number.

21343121323 is a deficient number, since it is larger than the sum of its proper divisors (300917).

21343121323 is a wasteful number, since it uses less digits than its factorization.

21343121323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300916.

The product of its digits is 2592, while the sum is 25.

Adding to 21343121323 its reverse (32312134312), we get a palindrome (53655255635).

The spelling of 21343121323 in words is "twenty-one billion, three hundred forty-three million, one hundred twenty-one thousand, three hundred twenty-three".