21535544121433 has 16 divisors (see below), whose sum is σ = 21688997049280. Its totient is φ = 21382739256384.

The previous prime is 21535544121383. The next prime is 21535544121521. The reversal of 21535544121433 is 33412144553512.

It is a cyclic number.

It is not a de Polignac number, because 21535544121433 - 2³³ = 21526954186841 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 21535544121433.

It is not an unprimeable number, because it can be changed into a prime (21535544124433) 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, 118451923 + ... + 118633591.

It is an arithmetic number, because the mean of its divisors is an integer number (1355562315580).

Almost surely, 2^{21535544121433} is an apocalyptic number.

It is an amenable number.

21535544121433 is a deficient number, since it is larger than the sum of its proper divisors (153452927847).

21535544121433 is a wasteful number, since it uses less digits than its factorization.

21535544121433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183448.

The product of its digits is 864000, while the sum is 43.

Adding to 21535544121433 its reverse (33412144553512), we get a palindrome (54947688674945).

The spelling of 21535544121433 in words is "twenty-one trillion, five hundred thirty-five billion, five hundred forty-four million, one hundred twenty-one thousand, four hundred thirty-three".