188381881 has 2 divisors, whose sum is σ = 188381882. Its totient is φ = 188381880.

The previous prime is 188381849. The next prime is 188381887. The reversal of 188381881 is 188183881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 179024400 + 9357481 = 13380^2 + 3059^2 .

It is a cyclic number.

It is not a de Polignac number, because 188381881 - 2⁵ = 188381849 is a prime.

It is a super-2 number, since 2×188381881² = 70975466178196322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (188381887) 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 as a sum of consecutive naturals, namely, 94190940 + 94190941.

It is an arithmetic number, because the mean of its divisors is an integer number (94190941).

Almost surely, 2^188381881 is an apocalyptic number.

It is an amenable number.

188381881 is a deficient number, since it is larger than the sum of its proper divisors (1).

188381881 is an equidigital number, since it uses as much as digits as its factorization.

188381881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 98304, while the sum is 46.

The square root of 188381881 is about 13725.2279033902. The cubic root of 188381881 is about 573.2530529908.

The spelling of 188381881 in words is "one hundred eighty-eight million, three hundred eighty-one thousand, eight hundred eighty-one".