9999988809 has 8 divisors (see below), whose sum is σ = 13340036640. Its totient is φ = 6663300096.

The previous prime is 9999988807. The next prime is 9999988811. The reversal of 9999988809 is 9088899999.

It is an interprime number because it is at equal distance from previous prime (9999988807) and next prime (9999988811).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 9999988809 - 2¹ = 9999988807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (9999988807) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 832824 + ... + 844745.

It is an arithmetic number, because the mean of its divisors is an integer number (1667504580).

Almost surely, 2^9999988809 is an apocalyptic number.

It is an amenable number.

9999988809 is a deficient number, since it is larger than the sum of its proper divisors (3340047831).

9999988809 is a wasteful number, since it uses less digits than its factorization.

9999988809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1679559.

The product of its (nonzero) digits is 272097792, while the sum is 78.

The square root of 9999988809 is about 99999.9440449843. The cubic root of 9999988809 is about 2154.4338863556.

The spelling of 9999988809 in words is "nine billion, nine hundred ninety-nine million, nine hundred eighty-eight thousand, eight hundred nine".