21500134400000 has 336 divisors, whose sum is σ = 54429033818880. Its totient is φ = 8490393600000.

The previous prime is 21500134399963. The next prime is 21500134400027. The reversal of 21500134400000 is 443100512.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2022394685 + ... + 2022405315.

It is an arithmetic number, because the mean of its divisors is an integer number (161991172080).

Almost surely, 2^{21500134400000} is an apocalyptic number.

21500134400000 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 21500134400000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27214516909440).

21500134400000 is an abundant number, since it is smaller than the sum of its proper divisors (32928899418880).

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

21500134400000 is an frugal number, since it uses more digits than its factorization.

21500134400000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10761 (or 10717 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

Adding to 21500134400000 its reverse (443100512), we get a palindrome (21500577500512).

The spelling of 21500134400000 in words is "twenty-one trillion, five hundred billion, one hundred thirty-four million, four hundred thousand".