199657868756991 has 8 divisors (see below), whose sum is σ = 266235813747120. Its totient is φ = 133092584802432.

The previous prime is 199657868756981. The next prime is 199657868757131.

199657868756991 is nontrivially palindromic in base 10.

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

It is not a de Polignac number, because 199657868756991 - 2⁵ = 199657868756959 is a prime.

It is a super-4 number, since 4×199657868756991⁴ (a number of 58 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199657868756981) 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, 3165222096 + ... + 3165285173.

It is an arithmetic number, because the mean of its divisors is an integer number (33279476718390).

Almost surely, 2^{199657868756991} is an apocalyptic number.

199657868756991 is a deficient number, since it is larger than the sum of its proper divisors (66577944990129).

199657868756991 is a wasteful number, since it uses less digits than its factorization.

199657868756991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6330517785.

The product of its digits is 111106598400, while the sum is 96.

The spelling of 199657868756991 in words is "one hundred ninety-nine trillion, six hundred fifty-seven billion, eight hundred sixty-eight million, seven hundred fifty-six thousand, nine hundred ninety-one".