199997 has 4 divisors (see below), whose sum is σ = 228576. Its totient is φ = 171420.

The previous prime is 199967. The next prime is 199999. The reversal of 199997 is 799991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 199997 - 2⁶ = 199933 is a prime.

It is a Duffinian 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 199997.

It is not an unprimeable number, because it can be changed into a prime (199999) 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, 14279 + ... + 14292.

It is an arithmetic number, because the mean of its divisors is an integer number (57144).

2¹⁹⁹⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

199997 is a deficient number, since it is larger than the sum of its proper divisors (28579).

199997 is an equidigital number, since it uses as much as digits as its factorization.

199997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28578.

The product of its digits is 45927, while the sum is 44.

The square root of 199997 is about 447.2102413854. The cubic root of 199997 is about 58.4800623610.

The spelling of 199997 in words is "one hundred ninety-nine thousand, nine hundred ninety-seven".