21115430563 has 2 divisors, whose sum is σ = 21115430564. Its totient is φ = 21115430562.

The previous prime is 21115430543. The next prime is 21115430573. The reversal of 21115430563 is 36503451112.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21115430563 is a prime.

It is a super-2 number, since 2×21115430563² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21115430543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10557715281 + 10557715282.

It is an arithmetic number, because the mean of its divisors is an integer number (10557715282).

Almost surely, 2^21115430563 is an apocalyptic number.

21115430563 is a deficient number, since it is larger than the sum of its proper divisors (1).

21115430563 is an equidigital number, since it uses as much as digits as its factorization.

21115430563 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10800, while the sum is 31.

Adding to 21115430563 its reverse (36503451112), we get a palindrome (57618881675).

The spelling of 21115430563 in words is "twenty-one billion, one hundred fifteen million, four hundred thirty thousand, five hundred sixty-three".