199516823 has 4 divisors (see below), whose sum is σ = 217654728. Its totient is φ = 181378920.

The previous prime is 199516771. The next prime is 199516841. The reversal of 199516823 is 328615991.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 328615991 = 11 ⋅29874181.

It is a cyclic number.

It is not a de Polignac number, because 199516823 - 2⁸ = 199516567 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 (199516523) 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, 9068936 + ... + 9068957.

It is an arithmetic number, because the mean of its divisors is an integer number (54413682).

Almost surely, 2^199516823 is an apocalyptic number.

199516823 is a deficient number, since it is larger than the sum of its proper divisors (18137905).

199516823 is a wasteful number, since it uses less digits than its factorization.

199516823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18137904.

The product of its digits is 116640, while the sum is 44.

The square root of 199516823 is about 14125.0424070160. The cubic root of 199516823 is about 584.3322285147.

The spelling of 199516823 in words is "one hundred ninety-nine million, five hundred sixteen thousand, eight hundred twenty-three".