9959840081 has 2 divisors, whose sum is σ = 9959840082. Its totient is φ = 9959840080.

The previous prime is 9959840063. The next prime is 9959840117. The reversal of 9959840081 is 1800489599.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9587543056 + 372297025 = 97916^2 + 19295^2 .

It is a cyclic number.

It is not a de Polignac number, because 9959840081 - 2¹⁸ = 9959577937 is a prime.

It is a super-2 number, since 2×9959840081² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (9959840281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4979920040 + 4979920041.

It is an arithmetic number, because the mean of its divisors is an integer number (4979920041).

Almost surely, 2^9959840081 is an apocalyptic number.

It is an amenable number.

9959840081 is a deficient number, since it is larger than the sum of its proper divisors (1).

9959840081 is an equidigital number, since it uses as much as digits as its factorization.

9959840081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 933120, while the sum is 53.

The square root of 9959840081 is about 99798.9983967775. The cubic root of 9959840081 is about 2151.5467565142.

The spelling of 9959840081 in words is "nine billion, nine hundred fifty-nine million, eight hundred forty thousand, eighty-one".