188199979981 has 12 divisors (see below), whose sum is σ = 203892216960. Its totient is φ = 173636358480.

The previous prime is 188199979973. The next prime is 188199979991. The reversal of 188199979981 is 189979991881.

It is a happy number.

It is not a de Polignac number, because 188199979981 - 2³ = 188199979973 is a prime.

It is a super-3 number, since 3×188199979981³ (a number of 35 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (188199979991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 62980 + ... + 616738.

It is an arithmetic number, because the mean of its divisors is an integer number (16991018080).

Almost surely, 2^188199979981 is an apocalyptic number.

It is an amenable number.

188199979981 is a deficient number, since it is larger than the sum of its proper divisors (15692236979).

188199979981 is a wasteful number, since it uses less digits than its factorization.

188199979981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 555796 (or 555783 counting only the distinct ones).

The product of its digits is 211631616, while the sum is 79.

The spelling of 188199979981 in words is "one hundred eighty-eight billion, one hundred ninety-nine million, nine hundred seventy-nine thousand, nine hundred eighty-one".