21113015563 has 2 divisors, whose sum is σ = 21113015564. Its totient is φ = 21113015562.

The previous prime is 21113015509. The next prime is 21113015569. The reversal of 21113015563 is 36551031112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21113015563 - 2²⁹ = 20576144651 is a prime.

It is not a weakly prime, because it can be changed into another prime (21113015569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10556507781 + 10556507782.

It is an arithmetic number, because the mean of its divisors is an integer number (10556507782).

Almost surely, 2^21113015563 is an apocalyptic number.

21113015563 is a deficient number, since it is larger than the sum of its proper divisors (1).

21113015563 is an equidigital number, since it uses as much as digits as its factorization.

21113015563 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2700, while the sum is 28.

Adding to 21113015563 its reverse (36551031112), we get a palindrome (57664046675).

The spelling of 21113015563 in words is "twenty-one billion, one hundred thirteen million, fifteen thousand, five hundred sixty-three".