199679 has 2 divisors, whose sum is σ = 199680. Its totient is φ = 199678.

The previous prime is 199673. The next prime is 199687. The reversal of 199679 is 976991.

It is a happy number.

It is a weak prime.

It is an emirp because it is prime and its reverse (976991) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199679 is a prime.

It is a Chen prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99839 + 99840.

It is an arithmetic number, because the mean of its divisors is an integer number (99840).

2¹⁹⁹⁶⁷⁹ is an apocalyptic number.

199679 is a deficient number, since it is larger than the sum of its proper divisors (1).

199679 is an equidigital number, since it uses as much as digits as its factorization.

199679 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30618, while the sum is 41.

The square root of 199679 is about 446.8545624697. The cubic root of 199679 is about 58.4490510210.

It can be divided in two parts, 199 and 679, that added together give a palindrome (878).

The spelling of 199679 in words is "one hundred ninety-nine thousand, six hundred seventy-nine".