21041543443 has 4 divisors (see below), whose sum is σ = 21041837568. Its totient is φ = 21041249320.

The previous prime is 21041543359. The next prime is 21041543531. The reversal of 21041543443 is 34434514012.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21041543443 - 2²¹ = 21039446291 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21041543843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37230 + ... + 208492.

It is an arithmetic number, because the mean of its divisors is an integer number (5260459392).

Almost surely, 2^21041543443 is an apocalyptic number.

21041543443 is a deficient number, since it is larger than the sum of its proper divisors (294125).

21041543443 is a wasteful number, since it uses less digits than its factorization.

21041543443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 294124.

The product of its (nonzero) digits is 23040, while the sum is 31.

The spelling of 21041543443 in words is "twenty-one billion, forty-one million, five hundred forty-three thousand, four hundred forty-three".