199145861 has 2 divisors, whose sum is σ = 199145862. Its totient is φ = 199145860.

The previous prime is 199145833. The next prime is 199145911. The reversal of 199145861 is 168541991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 182385025 + 16760836 = 13505^2 + 4094^2 .

It is a cyclic number.

It is not a de Polignac number, because 199145861 - 2⁶ = 199145797 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199145831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99572930 + 99572931.

It is an arithmetic number, because the mean of its divisors is an integer number (99572931).

Almost surely, 2^199145861 is an apocalyptic number.

It is an amenable number.

199145861 is a deficient number, since it is larger than the sum of its proper divisors (1).

199145861 is an equidigital number, since it uses as much as digits as its factorization.

199145861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77760, while the sum is 44.

The square root of 199145861 is about 14111.9049387388. The cubic root of 199145861 is about 583.9698538342.

The spelling of 199145861 in words is "one hundred ninety-nine million, one hundred forty-five thousand, eight hundred sixty-one".