21305541443 has 2 divisors, whose sum is σ = 21305541444. Its totient is φ = 21305541442.

The previous prime is 21305541421. The next prime is 21305541449. The reversal of 21305541443 is 34414550312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21305541443 - 2¹⁰ = 21305540419 is a prime.

It is not a weakly prime, because it can be changed into another prime (21305541449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10652770721 + 10652770722.

It is an arithmetic number, because the mean of its divisors is an integer number (10652770722).

Almost surely, 2^21305541443 is an apocalyptic number.

21305541443 is a deficient number, since it is larger than the sum of its proper divisors (1).

21305541443 is an equidigital number, since it uses as much as digits as its factorization.

21305541443 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28800, while the sum is 32.

The spelling of 21305541443 in words is "twenty-one billion, three hundred five million, five hundred forty-one thousand, four hundred forty-three".