191688 has 48 divisors (see below), whose sum is σ = 560880. Its totient is φ = 54432.

The previous prime is 191677. The next prime is 191689. The reversal of 191688 is 886191.

191688 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (191689) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1095 + ... + 1257.

It is an arithmetic number, because the mean of its divisors is an integer number (11685).

2¹⁹¹⁶⁸⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 191688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (280440).

191688 is an abundant number, since it is smaller than the sum of its proper divisors (369192).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

191688 is a wasteful number, since it uses less digits than its factorization.

191688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186 (or 175 counting only the distinct ones).

The product of its digits is 3456, while the sum is 33.

The square root of 191688 is about 437.8218815911. The cubic root of 191688 is about 57.6587171299.

The spelling of 191688 in words is "one hundred ninety-one thousand, six hundred eighty-eight".