21205444531533 has 8 divisors (see below), whose sum is σ = 28308364444896. Its totient is φ = 14119743819600.

The previous prime is 21205444531519. The next prime is 21205444531553. The reversal of 21205444531533 is 33513544450212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21205444531533 - 2¹⁸ = 21205444269389 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21205444531553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4304797483 + ... + 4304802408.

It is an arithmetic number, because the mean of its divisors is an integer number (3538545555612).

Almost surely, 2^{21205444531533} is an apocalyptic number.

It is an amenable number.

21205444531533 is a deficient number, since it is larger than the sum of its proper divisors (7102919913363).

21205444531533 is an equidigital number, since it uses as much as digits as its factorization.

21205444531533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8609600715.

The product of its (nonzero) digits is 864000, while the sum is 42.

Adding to 21205444531533 its reverse (33513544450212), we get a palindrome (54718988981745).

The spelling of 21205444531533 in words is "twenty-one trillion, two hundred five billion, four hundred forty-four million, five hundred thirty-one thousand, five hundred thirty-three".