21663536224441 has 2 divisors, whose sum is σ = 21663536224442. Its totient is φ = 21663536224440.

The previous prime is 21663536224411. The next prime is 21663536224457. The reversal of 21663536224441 is 14442263536612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19431213367225 + 2232322857216 = 4408085^2 + 1494096^2 .

It is a cyclic number.

It is not a de Polignac number, because 21663536224441 - 2⁷ = 21663536224313 is a prime.

It is not a weakly prime, because it can be changed into another prime (21663536224411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10831768112220 + 10831768112221.

It is an arithmetic number, because the mean of its divisors is an integer number (10831768112221).

Almost surely, 2^{21663536224441} is an apocalyptic number.

It is an amenable number.

21663536224441 is a deficient number, since it is larger than the sum of its proper divisors (1).

21663536224441 is an equidigital number, since it uses as much as digits as its factorization.

21663536224441 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4976640, while the sum is 49.

The spelling of 21663536224441 in words is "twenty-one trillion, six hundred sixty-three billion, five hundred thirty-six million, two hundred twenty-four thousand, four hundred forty-one".