21533454242323 has 4 divisors (see below), whose sum is σ = 21552527276440. Its totient is φ = 21514381208208.

The previous prime is 21533454242317. The next prime is 21533454242327. The reversal of 21533454242323 is 32324245433512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21533454242323 - 2¹⁷ = 21533454111251 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21533454242323.

It is not an unprimeable number, because it can be changed into a prime (21533454242327) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9536515365 + ... + 9536517622.

It is an arithmetic number, because the mean of its divisors is an integer number (5388131819110).

Almost surely, 2^{21533454242323} is an apocalyptic number.

21533454242323 is a deficient number, since it is larger than the sum of its proper divisors (19073034117).

21533454242323 is a wasteful number, since it uses less digits than its factorization.

21533454242323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19073034116.

The product of its digits is 2073600, while the sum is 43.

Adding to 21533454242323 its reverse (32324245433512), we get a palindrome (53857699675835).

The spelling of 21533454242323 in words is "twenty-one trillion, five hundred thirty-three billion, four hundred fifty-four million, two hundred forty-two thousand, three hundred twenty-three".