199539681 has 8 divisors (see below), whose sum is σ = 290239584. Its totient is φ = 120933120.

The previous prime is 199539677. The next prime is 199539721. The reversal of 199539681 is 186935991.

It is a happy number.

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

It is not a de Polignac number, because 199539681 - 2² = 199539677 is a prime.

It is a super-4 number, since 4×199539681⁴ (a number of 34 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (199539481) 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 7 ways as a sum of consecutive naturals, for example, 3023296 + ... + 3023361.

It is an arithmetic number, because the mean of its divisors is an integer number (36279948).

Almost surely, 2^199539681 is an apocalyptic number.

199539681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

199539681 is a deficient number, since it is larger than the sum of its proper divisors (90699903).

199539681 is a wasteful number, since it uses less digits than its factorization.

199539681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6046671.

The product of its digits is 524880, while the sum is 51.

The square root of 199539681 is about 14125.8515141566. The cubic root of 199539681 is about 584.3545426832.

The spelling of 199539681 in words is "one hundred ninety-nine million, five hundred thirty-nine thousand, six hundred eighty-one".