9909905 has 8 divisors (see below), whose sum is σ = 12182184. Its totient is φ = 7734400.

The previous prime is 9909901. The next prime is 9909917. The reversal of 9909905 is 5099099.

9909905 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Cunningham number, because it is equal to 3148²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 478864 + 9431041 = 692^2 + 3071^2 .

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

It is not a de Polignac number, because 9909905 - 2² = 9909901 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9909901) 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, 23966 + ... + 24375.

It is an arithmetic number, because the mean of its divisors is an integer number (1522773).

Almost surely, 2^9909905 is an apocalyptic number.

It is an amenable number.

9909905 is a deficient number, since it is larger than the sum of its proper divisors (2272279).

9909905 is a wasteful number, since it uses less digits than its factorization.

9909905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48387.

The product of its (nonzero) digits is 32805, while the sum is 41.

The square root of 9909905 is about 3148.0001588310. Note that the first 3 decimals coincide. The cubic root of 9909905 is about 214.7945034872.

The spelling of 9909905 in words is "nine million, nine hundred nine thousand, nine hundred five".