21306711441553 has 2 divisors, whose sum is σ = 21306711441554. Its totient is φ = 21306711441552.

The previous prime is 21306711441469. The next prime is 21306711441643. The reversal of 21306711441553 is 35514411760312.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17134566129664 + 4172145311889 = 4139392^2 + 2042583^2 .

It is a cyclic number.

It is not a de Polignac number, because 21306711441553 - 2³⁷ = 21169272488081 is a prime.

It is not a weakly prime, because it can be changed into another prime (21306711441853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10653355720776 + 10653355720777.

It is an arithmetic number, because the mean of its divisors is an integer number (10653355720777).

Almost surely, 2^{21306711441553} is an apocalyptic number.

It is an amenable number.

21306711441553 is a deficient number, since it is larger than the sum of its proper divisors (1).

21306711441553 is an equidigital number, since it uses as much as digits as its factorization.

21306711441553 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 302400, while the sum is 43.

The spelling of 21306711441553 in words is "twenty-one trillion, three hundred six billion, seven hundred eleven million, four hundred forty-one thousand, five hundred fifty-three".