199771001 has 2 divisors, whose sum is σ = 199771002. Its totient is φ = 199771000.

The previous prime is 199770971. The next prime is 199771003. The reversal of 199771001 is 100177991.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 117397225 + 82373776 = 10835^2 + 9076^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199771001 is a prime.

Together with 199771003, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (199771003) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99885500 + 99885501.

It is an arithmetic number, because the mean of its divisors is an integer number (99885501).

Almost surely, 2^199771001 is an apocalyptic number.

It is an amenable number.

199771001 is a deficient number, since it is larger than the sum of its proper divisors (1).

199771001 is an equidigital number, since it uses as much as digits as its factorization.

199771001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3969, while the sum is 35.

The square root of 199771001 is about 14134.0369675475. The cubic root of 199771001 is about 584.5802633551.

The spelling of 199771001 in words is "one hundred ninety-nine million, seven hundred seventy-one thousand, one".