199791 has 12 divisors (see below), whose sum is σ = 293280. Its totient is φ = 131040.

The previous prime is 199783. The next prime is 199799. The reversal of 199791 is 197991.

It is an interprime number because it is at equal distance from previous prime (199783) and next prime (199799).

It is not a de Polignac number, because 199791 - 2³ = 199783 is a prime.

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199799) 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, 571 + ... + 851.

It is an arithmetic number, because the mean of its divisors is an integer number (24440).

2¹⁹⁹⁷⁹¹ is an apocalyptic number.

199791 is a deficient number, since it is larger than the sum of its proper divisors (93489).

199791 is a wasteful number, since it uses less digits than its factorization.

199791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366 (or 363 counting only the distinct ones).

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

The square root of 199791 is about 446.9798653183. The cubic root of 199791 is about 58.4599770074.

It can be divided in two parts, 199 and 791, that added together give a triangular number (990 = T₄₄).

The spelling of 199791 in words is "one hundred ninety-nine thousand, seven hundred ninety-one".