21563350441 has 2 divisors, whose sum is σ = 21563350442. Its totient is φ = 21563350440.

The previous prime is 21563350429. The next prime is 21563350469. The reversal of 21563350441 is 14405336512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19908081216 + 1655269225 = 141096^2 + 40685^2 .

It is a cyclic number.

It is not a de Polignac number, because 21563350441 - 2⁷ = 21563350313 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21563350397 and 21563350406.

It is not a weakly prime, because it can be changed into another prime (21563350421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10781675220 + 10781675221.

It is an arithmetic number, because the mean of its divisors is an integer number (10781675221).

Almost surely, 2^21563350441 is an apocalyptic number.

It is an amenable number.

21563350441 is a deficient number, since it is larger than the sum of its proper divisors (1).

21563350441 is an equidigital number, since it uses as much as digits as its factorization.

21563350441 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 43200, while the sum is 34.

Adding to 21563350441 its reverse (14405336512), we get a palindrome (35968686953).

The spelling of 21563350441 in words is "twenty-one billion, five hundred sixty-three million, three hundred fifty thousand, four hundred forty-one".