21124353533 has 4 divisors (see below), whose sum is σ = 21329444448. Its totient is φ = 20919262620.

The previous prime is 21124353511. The next prime is 21124353541. The reversal of 21124353533 is 33535342112.

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 not a de Polignac number, because 21124353533 - 2¹⁸ = 21124091389 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 21124353533.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21124353563) 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, 102545303 + ... + 102545508.

It is an arithmetic number, because the mean of its divisors is an integer number (5332361112).

Almost surely, 2^21124353533 is an apocalyptic number.

It is an amenable number.

21124353533 is a deficient number, since it is larger than the sum of its proper divisors (205090915).

21124353533 is a wasteful number, since it uses less digits than its factorization.

21124353533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205090914.

The product of its digits is 32400, while the sum is 32.

Adding to 21124353533 its reverse (33535342112), we get a palindrome (54659695645).

The spelling of 21124353533 in words is "twenty-one billion, one hundred twenty-four million, three hundred fifty-three thousand, five hundred thirty-three".