99909990989 has 2 divisors, whose sum is σ = 99909990990. Its totient is φ = 99909990988.

The previous prime is 99909990977. The next prime is 99909991007. The reversal of 99909990989 is 98909990999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76429025764 + 23480965225 = 276458^2 + 153235^2 .

It is a cyclic number.

It is not a de Polignac number, because 99909990989 - 2³⁶ = 31190514253 is a prime.

It is a super-2 number, since 2×99909990989² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99909960989) 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, 49954995494 + 49954995495.

It is an arithmetic number, because the mean of its divisors is an integer number (49954995495).

Almost surely, 2^99909990989 is an apocalyptic number.

It is an amenable number.

99909990989 is a deficient number, since it is larger than the sum of its proper divisors (1).

99909990989 is an equidigital number, since it uses as much as digits as its factorization.

99909990989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 344373768, while the sum is 80.

The spelling of 99909990989 in words is "ninety-nine billion, nine hundred nine million, nine hundred ninety thousand, nine hundred eighty-nine".