21321344243 has 8 divisors (see below), whose sum is σ = 22224937680. Its totient is φ = 20428975840.

The previous prime is 21321344227. The next prime is 21321344293. The reversal of 21321344243 is 34244312312.

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 21321344243 - 2⁴ = 21321344227 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21321344203) 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, 2802380 + ... + 2809977.

It is an arithmetic number, because the mean of its divisors is an integer number (2778117210).

Almost surely, 2^21321344243 is an apocalyptic number.

21321344243 is a deficient number, since it is larger than the sum of its proper divisors (903593437).

21321344243 is a wasteful number, since it uses less digits than its factorization.

21321344243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5612517.

The product of its digits is 13824, while the sum is 29.

Adding to 21321344243 its reverse (34244312312), we get a palindrome (55565656555).

The spelling of 21321344243 in words is "twenty-one billion, three hundred twenty-one million, three hundred forty-four thousand, two hundred forty-three".