21543173458800 has 1440 divisors, whose sum is σ = 86003220441600. Its totient is φ = 4585897451520.

The previous prime is 21543173458799. The next prime is 21543173458801. The reversal of 21543173458800 is 885437134512.

It is an interprime number because it is at equal distance from previous prime (21543173458799) and next prime (21543173458801).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21543173458801) by changing a digit.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 8697283162 + ... + 8697285638.

It is an arithmetic number, because the mean of its divisors is an integer number (59724458640).

Almost surely, 2^{21543173458800} is an apocalyptic number.

21543173458800 is a gapful number since it is divisible by the number (20) 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 21543173458800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43001610220800).

21543173458800 is an abundant number, since it is smaller than the sum of its proper divisors (64460046982800).

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

21543173458800 is a wasteful number, since it uses less digits than its factorization.

21543173458800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2703 (or 2685 counting only the distinct ones).

The product of its (nonzero) digits is 3225600, while the sum is 51.

The spelling of 21543173458800 in words is "twenty-one trillion, five hundred forty-three billion, one hundred seventy-three million, four hundred fifty-eight thousand, eight hundred".