199865123149819 has 2 divisors, whose sum is σ = 199865123149820. Its totient is φ = 199865123149818.

The previous prime is 199865123149807. The next prime is 199865123149837. The reversal of 199865123149819 is 918941321568991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 199865123149819 - 2⁴⁷ = 59127634794491 is a prime.

It is a super-2 number, since 2×199865123149819² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (199865123149619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99932561574909 + 99932561574910.

It is an arithmetic number, because the mean of its divisors is an integer number (99932561574910).

Almost surely, 2^{199865123149819} is an apocalyptic number.

199865123149819 is a deficient number, since it is larger than the sum of its proper divisors (1).

199865123149819 is an equidigital number, since it uses as much as digits as its factorization.

199865123149819 is an evil number, because the sum of its binary digits is even.

The product of its digits is 302330880, while the sum is 76.

The spelling of 199865123149819 in words is "one hundred ninety-nine trillion, eight hundred sixty-five billion, one hundred twenty-three million, one hundred forty-nine thousand, eight hundred nineteen".