21544330405040 has 20 divisors (see below), whose sum is σ = 50090568191904. Its totient is φ = 8617732161984.

The previous prime is 21544330405027. The next prime is 21544330405043. The reversal of 21544330405040 is 4050403344512.

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (21544330405043) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 134652064952 + ... + 134652065111.

Almost surely, 2^{21544330405040} is an apocalyptic number.

21544330405040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21544330405040 is an abundant number, since it is smaller than the sum of its proper divisors (28546237786864).

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

21544330405040 is a wasteful number, since it uses less digits than its factorization.

21544330405040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269304130076 (or 269304130070 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 35.

Adding to 21544330405040 its reverse (4050403344512), we get a palindrome (25594733749552).

The spelling of 21544330405040 in words is "twenty-one trillion, five hundred forty-four billion, three hundred thirty million, four hundred five thousand, forty".