199191823 has 2 divisors, whose sum is σ = 199191824. Its totient is φ = 199191822.

The previous prime is 199191761. The next prime is 199191869. The reversal of 199191823 is 328191991.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199191823 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 199191823.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199191893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99595911 + 99595912.

It is an arithmetic number, because the mean of its divisors is an integer number (99595912).

Almost surely, 2^199191823 is an apocalyptic number.

199191823 is a deficient number, since it is larger than the sum of its proper divisors (1).

199191823 is an equidigital number, since it uses as much as digits as its factorization.

199191823 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34992, while the sum is 43.

The square root of 199191823 is about 14113.5333279799. The cubic root of 199191823 is about 584.0147762806.

The spelling of 199191823 in words is "one hundred ninety-nine million, one hundred ninety-one thousand, eight hundred twenty-three".