21544550204004 has 144 divisors (see below), whose sum is σ = 59849331534720. Its totient is φ = 6764758882560.

The previous prime is 21544550204003. The next prime is 21544550204063. The reversal of 21544550204004 is 40040205544512.

21544550204004 is a `hidden beast` number, since 2 + 1 + 5 + 44 + 550 + 20 + 40 + 0 + 4 = 666.

It is a super-3 number, since 3×21544550204004³ (a number of 41 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21544550204004.

It is not an unprimeable number, because it can be changed into a prime (21544550204003) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8165224 + ... + 10476639.

It is an arithmetic number, because the mean of its divisors is an integer number (415620357880).

Almost surely, 2^{21544550204004} is an apocalyptic number.

It is an amenable number.

21544550204004 is an abundant number, since it is smaller than the sum of its proper divisors (38304781330716).

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

21544550204004 is a wasteful number, since it uses less digits than its factorization.

21544550204004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18641952 (or 18641938 counting only the distinct ones).

The product of its (nonzero) digits is 128000, while the sum is 36.

Adding to 21544550204004 its reverse (40040205544512), we get a palindrome (61584755748516).

The spelling of 21544550204004 in words is "twenty-one trillion, five hundred forty-four billion, five hundred fifty million, two hundred four thousand, four".