21443413309 has 2 divisors, whose sum is σ = 21443413310. Its totient is φ = 21443413308.

The previous prime is 21443413283. The next prime is 21443413351. The reversal of 21443413309 is 90331434412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18658740409 + 2784672900 = 136597^2 + 52770^2 .

It is a cyclic number.

It is not a de Polignac number, because 21443413309 - 2⁹ = 21443412797 is a prime.

It is a super-5 number, since 5×21443413309⁵ (a number of 53 digits) contains 55555 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21443413399) 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, 10721706654 + 10721706655.

It is an arithmetic number, because the mean of its divisors is an integer number (10721706655).

Almost surely, 2^21443413309 is an apocalyptic number.

It is an amenable number.

21443413309 is a deficient number, since it is larger than the sum of its proper divisors (1).

21443413309 is an equidigital number, since it uses as much as digits as its factorization.

21443413309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 34.

The spelling of 21443413309 in words is "twenty-one billion, four hundred forty-three million, four hundred thirteen thousand, three hundred nine".