21533540425344 has 256 divisors, whose sum is σ = 66075804000000. Its totient is φ = 6895502659584.

The previous prime is 21533540425343. The next prime is 21533540425381. The reversal of 21533540425344 is 44352404533512.

21533540425344 is a `hidden beast` number, since 2 + 1 + 5 + 3 + 35 + 40 + 42 + 534 + 4 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 21533540425344.

It is not an unprimeable number, because it can be changed into a prime (21533540425343) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19404742 + ... + 20484410.

It is an arithmetic number, because the mean of its divisors is an integer number (258108609375).

Almost surely, 2^{21533540425344} is an apocalyptic number.

21533540425344 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21533540425344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33037902000000).

21533540425344 is an abundant number, since it is smaller than the sum of its proper divisors (44542263574656).

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

21533540425344 is a wasteful number, since it uses less digits than its factorization.

21533540425344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1079920 (or 1079902 counting only the distinct ones).

The product of its (nonzero) digits is 3456000, while the sum is 45.

Adding to 21533540425344 its reverse (44352404533512), we get a palindrome (65885944958856).

The spelling of 21533540425344 in words is "twenty-one trillion, five hundred thirty-three billion, five hundred forty million, four hundred twenty-five thousand, three hundred forty-four".