21005320599563 has 2 divisors, whose sum is σ = 21005320599564. Its totient is φ = 21005320599562.

The previous prime is 21005320599541. The next prime is 21005320599589. The reversal of 21005320599563 is 36599502350012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21005320599563 - 2⁶ = 21005320599499 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21005320499563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10502660299781 + 10502660299782.

It is an arithmetic number, because the mean of its divisors is an integer number (10502660299782).

Almost surely, 2^{21005320599563} is an apocalyptic number.

21005320599563 is a deficient number, since it is larger than the sum of its proper divisors (1).

21005320599563 is an equidigital number, since it uses as much as digits as its factorization.

21005320599563 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2187000, while the sum is 50.

The spelling of 21005320599563 in words is "twenty-one trillion, five billion, three hundred twenty million, five hundred ninety-nine thousand, five hundred sixty-three".