199640751181 has 4 divisors (see below), whose sum is σ = 204283559392. Its totient is φ = 194997942972.

The previous prime is 199640751131. The next prime is 199640751199. The reversal of 199640751181 is 181157046991.

It is a happy number.

199640751181 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 199640751181 - 2²⁵ = 199607196749 is a prime.

It is a super-2 number, since 2×199640751181² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199640751131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2321404041 + ... + 2321404126.

It is an arithmetic number, because the mean of its divisors is an integer number (51070889848).

Almost surely, 2^199640751181 is an apocalyptic number.

It is an amenable number.

199640751181 is a deficient number, since it is larger than the sum of its proper divisors (4642808211).

199640751181 is an equidigital number, since it uses as much as digits as its factorization.

199640751181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4642808210.

The product of its (nonzero) digits is 544320, while the sum is 52.

The spelling of 199640751181 in words is "one hundred ninety-nine billion, six hundred forty million, seven hundred fifty-one thousand, one hundred eighty-one".