9944208221 has 2 divisors, whose sum is σ = 9944208222. Its totient is φ = 9944208220.

The previous prime is 9944208167. The next prime is 9944208223. The reversal of 9944208221 is 1228024499.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5655792025 + 4288416196 = 75205^2 + 65486^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9944208221 is a prime.

Together with 9944208223, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9944208223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4972104110 + 4972104111.

It is an arithmetic number, because the mean of its divisors is an integer number (4972104111).

Almost surely, 2^9944208221 is an apocalyptic number.

It is an amenable number.

9944208221 is a deficient number, since it is larger than the sum of its proper divisors (1).

9944208221 is an equidigital number, since it uses as much as digits as its factorization.

9944208221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 9944208221 is about 99720.6509254728. The cubic root of 9944208221 is about 2150.4205574273.

The spelling of 9944208221 in words is "nine billion, nine hundred forty-four million, two hundred eight thousand, two hundred twenty-one".