21244305533 has 6 divisors (see below), whose sum is σ = 23351178942. Its totient is φ = 19313004920.

The previous prime is 21244305499. The next prime is 21244305539. The reversal of 21244305533 is 33550344212.

It can be written as a sum of positive squares in only one way, i.e., 14370734884 + 6873570649 = 119878^2 + 82907^2 .

It is not a de Polignac number, because 21244305533 - 2¹⁰ = 21244304509 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 21244305533.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21244305539) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 87786266 + ... + 87786507.

It is an arithmetic number, because the mean of its divisors is an integer number (3891863157).

Almost surely, 2^21244305533 is an apocalyptic number.

It is an amenable number.

21244305533 is a deficient number, since it is larger than the sum of its proper divisors (2106873409).

21244305533 is a wasteful number, since it uses less digits than its factorization.

21244305533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175572795 (or 175572784 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 32.

Adding to 21244305533 its reverse (33550344212), we get a palindrome (54794649745).

The spelling of 21244305533 in words is "twenty-one billion, two hundred forty-four million, three hundred five thousand, five hundred thirty-three".