199838661 has 16 divisors (see below), whose sum is σ = 292289088. Its totient is φ = 120441600.

The previous prime is 199838647. The next prime is 199838663. The reversal of 199838661 is 166838991.

It is not a de Polignac number, because 199838661 - 2⁷ = 199838533 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199838663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10756 + ... + 22701.

It is an arithmetic number, because the mean of its divisors is an integer number (18268068).

Almost surely, 2^199838661 is an apocalyptic number.

199838661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

199838661 is a deficient number, since it is larger than the sum of its proper divisors (92450427).

199838661 is a wasteful number, since it uses less digits than its factorization.

199838661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33652.

The product of its digits is 559872, while the sum is 51.

The square root of 199838661 is about 14136.4302778318. The cubic root of 199838661 is about 584.6462526393.

The spelling of 199838661 in words is "one hundred ninety-nine million, eight hundred thirty-eight thousand, six hundred sixty-one".