999398905 has 16 divisors (see below), whose sum is σ = 1233644544. Its totient is φ = 776805120.

The previous prime is 999398891. The next prime is 999398963. The reversal of 999398905 is 509893999.

It is a de Polignac number, because none of the positive numbers 2^k-999398905 is a prime.

It is an unprimeable number.

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 in 15 ways as a sum of consecutive naturals, for example, 28897 + ... + 53233.

It is an arithmetic number, because the mean of its divisors is an integer number (77102784).

Almost surely, 2^999398905 is an apocalyptic number.

It is an amenable number.

999398905 is a deficient number, since it is larger than the sum of its proper divisors (234245639).

999398905 is a wasteful number, since it uses less digits than its factorization.

999398905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24576.

The product of its (nonzero) digits is 7085880, while the sum is 61.

The square root of 999398905 is about 31613.2710265800. The cubic root of 999398905 is about 999.7995948405.

The spelling of 999398905 in words is "nine hundred ninety-nine million, three hundred ninety-eight thousand, nine hundred five".