199959661 has 8 divisors (see below), whose sum is σ = 230969664. Its totient is φ = 171088320.

The previous prime is 199959653. The next prime is 199959707. The reversal of 199959661 is 166959991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 199959661 - 2³ = 199959653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199954661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 534465 + ... + 534838.

It is an arithmetic number, because the mean of its divisors is an integer number (28871208).

Almost surely, 2^199959661 is an apocalyptic number.

199959661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

199959661 is a deficient number, since it is larger than the sum of its proper divisors (31010003).

199959661 is a wasteful number, since it uses less digits than its factorization.

199959661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1069331.

The product of its digits is 1180980, while the sum is 55.

The square root of 199959661 is about 14140.7093527871. The cubic root of 199959661 is about 584.7642276817.

The spelling of 199959661 in words is "one hundred ninety-nine million, nine hundred fifty-nine thousand, six hundred sixty-one".