199101661 has 4 divisors (see below), whose sum is σ = 217201824. Its totient is φ = 181001500.

The previous prime is 199101631. The next prime is 199101667. The reversal of 199101661 is 166101991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 199101661 - 2¹⁵ = 199068893 is a prime.

199101661 is a strobogrammatic number because it is the same when read upside-down.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199101667) 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 in 3 ways as a sum of consecutive naturals, for example, 9050065 + ... + 9050086.

It is an arithmetic number, because the mean of its divisors is an integer number (54300456).

Almost surely, 2^199101661 is an apocalyptic number.

199101661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

199101661 is a deficient number, since it is larger than the sum of its proper divisors (18100163).

199101661 is a wasteful number, since it uses less digits than its factorization.

199101661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18100162.

The product of its (nonzero) digits is 2916, while the sum is 34.

The square root of 199101661 is about 14110.3387982004. The cubic root of 199101661 is about 583.9266470154.

The spelling of 199101661 in words is "one hundred ninety-nine million, one hundred one thousand, six hundred sixty-one".