9908455721 has 2 divisors, whose sum is σ = 9908455722. Its totient is φ = 9908455720.

The previous prime is 9908455703. The next prime is 9908455769. The reversal of 9908455721 is 1275548099.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5735941696 + 4172514025 = 75736^2 + 64595^2 .

It is a cyclic number.

It is not a de Polignac number, because 9908455721 - 2³⁰ = 8834713897 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 9908455721.

It is not a weakly prime, because it can be changed into another prime (9908455021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4954227860 + 4954227861.

It is an arithmetic number, because the mean of its divisors is an integer number (4954227861).

Almost surely, 2^9908455721 is an apocalyptic number.

It is an amenable number.

9908455721 is a deficient number, since it is larger than the sum of its proper divisors (1).

9908455721 is an equidigital number, since it uses as much as digits as its factorization.

9908455721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 907200, while the sum is 50.

The square root of 9908455721 is about 99541.2262381773. The cubic root of 9908455721 is about 2147.8403206697.

The spelling of 9908455721 in words is "nine billion, nine hundred eight million, four hundred fifty-five thousand, seven hundred twenty-one".