199447187 has 4 divisors (see below), whose sum is σ = 199583160. Its totient is φ = 199311216.

The previous prime is 199447177. The next prime is 199447189. The reversal of 199447187 is 781744991.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 199447187 - 2¹⁸ = 199185043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199447189) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65762 + ... + 68727.

It is an arithmetic number, because the mean of its divisors is an integer number (49895790).

Almost surely, 2^199447187 is an apocalyptic number.

199447187 is a deficient number, since it is larger than the sum of its proper divisors (135973).

199447187 is a wasteful number, since it uses less digits than its factorization.

199447187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135972.

The product of its digits is 508032, while the sum is 50.

The square root of 199447187 is about 14122.5772081444. The cubic root of 199447187 is about 584.2642387694.

The spelling of 199447187 in words is "one hundred ninety-nine million, four hundred forty-seven thousand, one hundred eighty-seven".