199951 has 4 divisors (see below), whose sum is σ = 203400. Its totient is φ = 196504.

The previous prime is 199933. The next prime is 199961. The reversal of 199951 is 159991.

199951 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 199951 - 2¹⁷ = 68879 is a prime.

It is a Duffinian number.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 1636 + ... + 1753.

It is an arithmetic number, because the mean of its divisors is an integer number (50850).

2¹⁹⁹⁹⁵¹ is an apocalyptic number.

199951 is a deficient number, since it is larger than the sum of its proper divisors (3449).

199951 is an equidigital number, since it uses as much as digits as its factorization.

199951 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3448.

The product of its digits is 3645, while the sum is 34.

The square root of 199951 is about 447.1588084786. The cubic root of 199951 is about 58.4755784785.

The spelling of 199951 in words is "one hundred ninety-nine thousand, nine hundred fifty-one".