21543500534512 has 40 divisors (see below), whose sum is σ = 45537502556160. Its totient is φ = 9791989183680.

The previous prime is 21543500534489. The next prime is 21543500534513.

21543500534512 is nontrivially palindromic in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21543500534513) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 198033 + ... + 6567055.

It is an arithmetic number, because the mean of its divisors is an integer number (1138437563904).

Almost surely, 2^{21543500534512} is an apocalyptic number.

21543500534512 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21543500534512 is an abundant number, since it is smaller than the sum of its proper divisors (23994002021648).

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

21543500534512 is a wasteful number, since it uses less digits than its factorization.

21543500534512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6388261 (or 6388255 counting only the distinct ones).

The product of its (nonzero) digits is 360000, while the sum is 40.

The spelling of 21543500534512 in words is "twenty-one trillion, five hundred forty-three billion, five hundred million, five hundred thirty-four thousand, five hundred twelve".