21303355544 has 16 divisors (see below), whose sum is σ = 39968579520. Its totient is φ = 10645067680.

The previous prime is 21303355529. The next prime is 21303355553. The reversal of 21303355544 is 44555330312.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 812552 + ... + 838359.

It is an arithmetic number, because the mean of its divisors is an integer number (2498036220).

Almost surely, 2^21303355544 is an apocalyptic number.

It is an amenable number.

21303355544 is a deficient number, since it is larger than the sum of its proper divisors (18665223976).

21303355544 is a wasteful number, since it uses less digits than its factorization.

21303355544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1652530 (or 1652526 counting only the distinct ones).

The product of its (nonzero) digits is 108000, while the sum is 35.

Adding to 21303355544 its reverse (44555330312), we get a palindrome (65858685856).

The spelling of 21303355544 in words is "twenty-one billion, three hundred three million, three hundred fifty-five thousand, five hundred forty-four".