21069563 has 2 divisors, whose sum is σ = 21069564. Its totient is φ = 21069562.

The previous prime is 21069547. The next prime is 21069569. The reversal of 21069563 is 36596012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21069563 - 2⁴ = 21069547 is a prime.

It is not a weakly prime, because it can be changed into another prime (21069569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10534781 + 10534782.

It is an arithmetic number, because the mean of its divisors is an integer number (10534782).

Almost surely, 2^21069563 is an apocalyptic number.

21069563 is a deficient number, since it is larger than the sum of its proper divisors (1).

21069563 is an equidigital number, since it uses as much as digits as its factorization.

21069563 is an evil number, because the sum of its binary digits is even.

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

The square root of 21069563 is about 4590.1593654251. The cubic root of 21069563 is about 276.1967152881.

The spelling of 21069563 in words is "twenty-one million, sixty-nine thousand, five hundred sixty-three".