199969809161 has 2 divisors, whose sum is σ = 199969809162. Its totient is φ = 199969809160.

The previous prime is 199969809103. The next prime is 199969809203. The reversal of 199969809161 is 161908969991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 182162508025 + 17807301136 = 426805^2 + 133444^2 .

It is an emirp because it is prime and its reverse (161908969991) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 191608696661 and 166696806191.

It is a cyclic number.

It is not a de Polignac number, because 199969809161 - 2¹⁴ = 199969792777 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 199969809091 and 199969809100.

It is not a weakly prime, because it can be changed into another prime (199969829161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99984904580 + 99984904581.

It is an arithmetic number, because the mean of its divisors is an integer number (99984904581).

Almost surely, 2^199969809161 is an apocalyptic number.

It is an amenable number.

199969809161 is a deficient number, since it is larger than the sum of its proper divisors (1).

199969809161 is an equidigital number, since it uses as much as digits as its factorization.

199969809161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17006112, while the sum is 68.

The spelling of 199969809161 in words is "one hundred ninety-nine billion, nine hundred sixty-nine million, eight hundred nine thousand, one hundred sixty-one".