188861 has 2 divisors, whose sum is σ = 188862. Its totient is φ = 188860.

The previous prime is 188857. The next prime is 188863. The reversal of 188861 is 168881.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 164836 + 24025 = 406^2 + 155^2 .

It is a cyclic number.

It is not a de Polignac number, because 188861 - 2² = 188857 is a prime.

Together with 188863, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (188863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94430 + 94431.

It is an arithmetic number, because the mean of its divisors is an integer number (94431).

2¹⁸⁸⁸⁶¹ is an apocalyptic number.

It is an amenable number.

188861 is a deficient number, since it is larger than the sum of its proper divisors (1).

188861 is an equidigital number, since it uses as much as digits as its factorization.

188861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3072, while the sum is 32.

The square root of 188861 is about 434.5814077938. The cubic root of 188861 is about 57.3738633855.

The spelling of 188861 in words is "one hundred eighty-eight thousand, eight hundred sixty-one".