199171901 has 2 divisors, whose sum is σ = 199171902. Its totient is φ = 199171900.

The previous prime is 199171897. The next prime is 199171909. The reversal of 199171901 is 109171991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 105062500 + 94109401 = 10250^2 + 9701^2 .

It is a cyclic number.

It is not a de Polignac number, because 199171901 - 2² = 199171897 is a prime.

It is a super-2 number, since 2×199171901² = 79338892295907602, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199171909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99585950 + 99585951.

It is an arithmetic number, because the mean of its divisors is an integer number (99585951).

Almost surely, 2^199171901 is an apocalyptic number.

It is an amenable number.

199171901 is a deficient number, since it is larger than the sum of its proper divisors (1).

199171901 is an equidigital number, since it uses as much as digits as its factorization.

199171901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5103, while the sum is 38.

The square root of 199171901 is about 14112.8275338431. The cubic root of 199171901 is about 583.9953057185.

The spelling of 199171901 in words is "one hundred ninety-nine million, one hundred seventy-one thousand, nine hundred one".