199971 has 12 divisors (see below), whose sum is σ = 306072. Its totient is φ = 125376.

The previous prime is 199967. The next prime is 199999. The reversal of 199971 is 179991.

It is not a de Polignac number, because 199971 - 2² = 199967 is a prime.

199971 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 199971.

It is not an unprimeable number, because it can be changed into a prime (199921) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 501 + ... + 806.

It is an arithmetic number, because the mean of its divisors is an integer number (25506).

2¹⁹⁹⁹⁷¹ is an apocalyptic number.

199971 is a deficient number, since it is larger than the sum of its proper divisors (106101).

199971 is a wasteful number, since it uses less digits than its factorization.

199971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1330 (or 1327 counting only the distinct ones).

The product of its digits is 5103, while the sum is 36.

The square root of 199971 is about 447.1811713389. The cubic root of 199971 is about 58.4775280771.

The spelling of 199971 in words is "one hundred ninety-nine thousand, nine hundred seventy-one".