21821284543 has 2 divisors, whose sum is σ = 21821284544. Its totient is φ = 21821284542.

The previous prime is 21821284487. The next prime is 21821284549. The reversal of 21821284543 is 34548212812.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21821284543 - 2²¹ = 21819187391 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21821284496 and 21821284505.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21821284549) 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 as a sum of consecutive naturals, namely, 10910642271 + 10910642272.

It is an arithmetic number, because the mean of its divisors is an integer number (10910642272).

Almost surely, 2^21821284543 is an apocalyptic number.

21821284543 is a deficient number, since it is larger than the sum of its proper divisors (1).

21821284543 is an equidigital number, since it uses as much as digits as its factorization.

21821284543 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 122880, while the sum is 40.

The spelling of 21821284543 in words is "twenty-one billion, eight hundred twenty-one million, two hundred eighty-four thousand, five hundred forty-three".