9911455921 has 2 divisors, whose sum is σ = 9911455922. Its totient is φ = 9911455920.

The previous prime is 9911455913. The next prime is 9911455949. The reversal of 9911455921 is 1295541199.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8071045921 + 1840410000 = 89839^2 + 42900^2 .

It is a cyclic number.

It is not a de Polignac number, because 9911455921 - 2³ = 9911455913 is a prime.

It is not a weakly prime, because it can be changed into another prime (9911455901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4955727960 + 4955727961.

It is an arithmetic number, because the mean of its divisors is an integer number (4955727961).

Almost surely, 2^9911455921 is an apocalyptic number.

It is an amenable number.

9911455921 is a deficient number, since it is larger than the sum of its proper divisors (1).

9911455921 is an equidigital number, since it uses as much as digits as its factorization.

9911455921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145800, while the sum is 46.

The square root of 9911455921 is about 99556.2952354094. The cubic root of 9911455921 is about 2148.0570816676.

The spelling of 9911455921 in words is "nine billion, nine hundred eleven million, four hundred fifty-five thousand, nine hundred twenty-one".