21063569 has 2 divisors, whose sum is σ = 21063570. Its totient is φ = 21063568.

The previous prime is 21063529. The next prime is 21063673. The reversal of 21063569 is 96536012.

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., 19254544 + 1809025 = 4388^2 + 1345^2 .

It is a cyclic number.

It is not a de Polignac number, because 21063569 - 2²⁰ = 20014993 is a prime.

It is a super-2 number, since 2×21063569² = 887347878035522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21063529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10531784 + 10531785.

It is an arithmetic number, because the mean of its divisors is an integer number (10531785).

Almost surely, 2^21063569 is an apocalyptic number.

It is an amenable number.

21063569 is a deficient number, since it is larger than the sum of its proper divisors (1).

21063569 is an equidigital number, since it uses as much as digits as its factorization.

21063569 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9720, while the sum is 32.

The square root of 21063569 is about 4589.5064004749. The cubic root of 21063569 is about 276.1705214189.

The spelling of 21063569 in words is "twenty-one million, sixty-three thousand, five hundred sixty-nine".