9885408821 has 2 divisors, whose sum is σ = 9885408822. Its totient is φ = 9885408820.

The previous prime is 9885408781. The next prime is 9885408839. The reversal of 9885408821 is 1288045889.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8052370225 + 1833038596 = 89735^2 + 42814^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9885408821 is a prime.

It is a super-2 number, since 2×9885408821² (a number of 21 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9885404821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4942704410 + 4942704411.

It is an arithmetic number, because the mean of its divisors is an integer number (4942704411).

Almost surely, 2^9885408821 is an apocalyptic number.

It is an amenable number.

9885408821 is a deficient number, since it is larger than the sum of its proper divisors (1).

9885408821 is an equidigital number, since it uses as much as digits as its factorization.

9885408821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1474560, while the sum is 53.

The square root of 9885408821 is about 99425.3932403589. The cubic root of 9885408821 is about 2146.1737478053.

The spelling of 9885408821 in words is "nine billion, eight hundred eighty-five million, four hundred eight thousand, eight hundred twenty-one".