21115352563 has 2 divisors, whose sum is σ = 21115352564. Its totient is φ = 21115352562.

The previous prime is 21115352549. The next prime is 21115352591. The reversal of 21115352563 is 36525351112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21115352563 - 2²⁵ = 21081798131 is a prime.

It is a super-2 number, since 2×21115352563² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21115352263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10557676281 + 10557676282.

It is an arithmetic number, because the mean of its divisors is an integer number (10557676282).

Almost surely, 2^21115352563 is an apocalyptic number.

21115352563 is a deficient number, since it is larger than the sum of its proper divisors (1).

21115352563 is an equidigital number, since it uses as much as digits as its factorization.

21115352563 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27000, while the sum is 34.

The spelling of 21115352563 in words is "twenty-one billion, one hundred fifteen million, three hundred fifty-two thousand, five hundred sixty-three".