199400561 has 2 divisors, whose sum is σ = 199400562. Its totient is φ = 199400560.

The previous prime is 199400557. The next prime is 199400581. The reversal of 199400561 is 165004991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 169806961 + 29593600 = 13031^2 + 5440^2 .

It is an emirp because it is prime and its reverse (165004991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 199400561 - 2² = 199400557 is a prime.

It is a super-2 number, since 2×199400561² = 79521167454229442, which contains 22 as substring.

It is a Chen prime.

It is equal to p_11047589 and since 199400561 and 11047589 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (199400581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99700280 + 99700281.

It is an arithmetic number, because the mean of its divisors is an integer number (99700281).

Almost surely, 2^199400561 is an apocalyptic number.

It is an amenable number.

199400561 is a deficient number, since it is larger than the sum of its proper divisors (1).

199400561 is an equidigital number, since it uses as much as digits as its factorization.

199400561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9720, while the sum is 35.

The square root of 199400561 is about 14120.9263506329. The cubic root of 199400561 is about 584.2187062019.

The spelling of 199400561 in words is "one hundred ninety-nine million, four hundred thousand, five hundred sixty-one".