188888699981 has 2 divisors, whose sum is σ = 188888699982. Its totient is φ = 188888699980.

The previous prime is 188888699969. The next prime is 188888700041. The reversal of 188888699981 is 189996888881.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 131341008100 + 57547691881 = 362410^2 + 239891^2 .

It is a cyclic number.

It is not a de Polignac number, because 188888699981 - 2³⁰ = 187814958157 is a prime.

It is a super-2 number, since 2×188888699981² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 188888699981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (188888699941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94444349990 + 94444349991.

It is an arithmetic number, because the mean of its divisors is an integer number (94444349991).

Almost surely, 2^188888699981 is an apocalyptic number.

It is an amenable number.

188888699981 is a deficient number, since it is larger than the sum of its proper divisors (1).

188888699981 is an equidigital number, since it uses as much as digits as its factorization.

188888699981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1146617856, while the sum is 83.

The spelling of 188888699981 in words is "one hundred eighty-eight billion, eight hundred eighty-eight million, six hundred ninety-nine thousand, nine hundred eighty-one".