21361300544 has 56 divisors (see below), whose sum is σ = 44641312800. Its totient is φ = 10113638400.

The previous prime is 21361300537. The next prime is 21361300549. The reversal of 21361300544 is 44500316312.

It is not an unprimeable number, because it can be changed into a prime (21361300549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4446944 + ... + 4451744.

It is an arithmetic number, because the mean of its divisors is an integer number (797166300).

Almost surely, 2^21361300544 is an apocalyptic number.

It is an amenable number.

21361300544 is an abundant number, since it is smaller than the sum of its proper divisors (23280012256).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21361300544 is a wasteful number, since it uses less digits than its factorization.

21361300544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8491 (or 8481 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 29.

Adding to 21361300544 its reverse (44500316312), we get a palindrome (65861616856).

The spelling of 21361300544 in words is "twenty-one billion, three hundred sixty-one million, three hundred thousand, five hundred forty-four".