21220033447 has 2 divisors, whose sum is σ = 21220033448. Its totient is φ = 21220033446.

The previous prime is 21220033411. The next prime is 21220033487. The reversal of 21220033447 is 74433002212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21220033447 - 2¹⁹ = 21219509159 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21220033487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610016723 + 10610016724.

It is an arithmetic number, because the mean of its divisors is an integer number (10610016724).

Almost surely, 2^21220033447 is an apocalyptic number.

21220033447 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220033447 is an equidigital number, since it uses as much as digits as its factorization.

21220033447 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 28.

Adding to 21220033447 its reverse (74433002212), we get a palindrome (95653035659).

The spelling of 21220033447 in words is "twenty-one billion, two hundred twenty million, thirty-three thousand, four hundred forty-seven".