199643906 has 96 divisors (see below), whose sum is σ = 411816960. Its totient is φ = 70308000.

The previous prime is 199643881. The next prime is 199643947. The reversal of 199643906 is 609346991.

It is a congruent number.

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 in 47 ways as a sum of consecutive naturals, for example, 2811851 + ... + 2811921.

It is an arithmetic number, because the mean of its divisors is an integer number (4289760).

Almost surely, 2^199643906 is an apocalyptic number.

199643906 is an abundant number, since it is smaller than the sum of its proper divisors (212173054).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

199643906 is a wasteful number, since it uses less digits than its factorization.

199643906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172 (or 141 counting only the distinct ones).

The product of its (nonzero) digits is 314928, while the sum is 47.

The square root of 199643906 is about 14129.5401906785. The cubic root of 199643906 is about 584.4562663955.

The spelling of 199643906 in words is "one hundred ninety-nine million, six hundred forty-three thousand, nine hundred six".