21563007211 has 2 divisors, whose sum is σ = 21563007212. Its totient is φ = 21563007210.

The previous prime is 21563007197. The next prime is 21563007239. The reversal of 21563007211 is 11270036512.

It is a happy number.

It is an a-pointer prime, because the next prime (21563007239) can be obtained adding 21563007211 to its sum of digits (28).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21563007211 - 2²⁷ = 21428789483 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21563007211.

It is not a weakly prime, because it can be changed into another prime (21563007611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10781503605 + 10781503606.

It is an arithmetic number, because the mean of its divisors is an integer number (10781503606).

Almost surely, 2^21563007211 is an apocalyptic number.

21563007211 is a deficient number, since it is larger than the sum of its proper divisors (1).

21563007211 is an equidigital number, since it uses as much as digits as its factorization.

21563007211 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2520, while the sum is 28.

The spelling of 21563007211 in words is "twenty-one billion, five hundred sixty-three million, seven thousand, two hundred eleven".