21154533213543 has 16 divisors (see below), whose sum is σ = 29865383944416. Its totient is φ = 13273361233920.

The previous prime is 21154533213529. The next prime is 21154533213547. The reversal of 21154533213543 is 34531233545112.

It is not a de Polignac number, because 21154533213543 - 2⁹ = 21154533213031 is a prime.

It is a super-2 number, since 2×21154533213543² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21154533213495 and 21154533213504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21154533213547) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9431055 + ... + 11456607.

It is an arithmetic number, because the mean of its divisors is an integer number (1866586496526).

Almost surely, 2^{21154533213543} is an apocalyptic number.

21154533213543 is a deficient number, since it is larger than the sum of its proper divisors (8710850730873).

21154533213543 is a wasteful number, since it uses less digits than its factorization.

21154533213543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2230354.

The product of its digits is 648000, while the sum is 42.

Adding to 21154533213543 its reverse (34531233545112), we get a palindrome (55685766758655).

The spelling of 21154533213543 in words is "twenty-one trillion, one hundred fifty-four billion, five hundred thirty-three million, two hundred thirteen thousand, five hundred forty-three".