199639123 has 2 divisors, whose sum is σ = 199639124. Its totient is φ = 199639122.

The previous prime is 199639117. The next prime is 199639129. The reversal of 199639123 is 321936991.

It is a balanced prime because it is at equal distance from previous prime (199639117) and next prime (199639129).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199639123 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 199639123.

It is not a weakly prime, because it can be changed into another prime (199639129) 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, 99819561 + 99819562.

It is an arithmetic number, because the mean of its divisors is an integer number (99819562).

Almost surely, 2^199639123 is an apocalyptic number.

199639123 is a deficient number, since it is larger than the sum of its proper divisors (1).

199639123 is an equidigital number, since it uses as much as digits as its factorization.

199639123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 78732, while the sum is 43.

The square root of 199639123 is about 14129.3709343339. The cubic root of 199639123 is about 584.4515989575.

The spelling of 199639123 in words is "one hundred ninety-nine million, six hundred thirty-nine thousand, one hundred twenty-three".