9905906 has 4 divisors (see below), whose sum is σ = 14858862. Its totient is φ = 4952952.

The previous prime is 9905891. The next prime is 9905911. The reversal of 9905906 is 6095099.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6095099 = 1319 ⋅4621.

It can be written as a sum of positive squares in only one way, i.e., 7317025 + 2588881 = 2705^2 + 1609^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 9905906.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2476475 + ... + 2476478.

Almost surely, 2^9905906 is an apocalyptic number.

9905906 is a deficient number, since it is larger than the sum of its proper divisors (4952956).

9905906 is a wasteful number, since it uses less digits than its factorization.

9905906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4952955.

The product of its (nonzero) digits is 21870, while the sum is 38.

The square root of 9905906 is about 3147.3649295879. The cubic root of 9905906 is about 214.7656071865.

The spelling of 9905906 in words is "nine million, nine hundred five thousand, nine hundred six".