199991331 has 6 divisors (see below), whose sum is σ = 288876380. Its totient is φ = 133327548.

The previous prime is 199991303. The next prime is 199991339. The reversal of 199991331 is 133199991.

199991331 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 199991331 - 2⁵ = 199991299 is a prime.

It is a super-3 number, since 3×199991331³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a nude number because it is divisible by every one of its digits.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199991339) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11110621 + ... + 11110638.

Almost surely, 2^199991331 is an apocalyptic number.

199991331 is a deficient number, since it is larger than the sum of its proper divisors (88885049).

199991331 is a wasteful number, since it uses less digits than its factorization.

199991331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22221265 (or 22221262 counting only the distinct ones).

The product of its digits is 59049, while the sum is 45.

The square root of 199991331 is about 14141.8291249753. The cubic root of 199991331 is about 584.7950980839.

The spelling of 199991331 in words is "one hundred ninety-nine million, nine hundred ninety-one thousand, three hundred thirty-one".