211688 has 16 divisors (see below), whose sum is σ = 406080. Its totient is φ = 103408.

The previous prime is 211681. The next prime is 211691. The reversal of 211688 is 886112.

211688 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (211681) by changing a digit.

211688 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95 + ... + 657.

It is an arithmetic number, because the mean of its divisors is an integer number (25380).

2²¹¹⁶⁸⁸ is an apocalyptic number.

It is an amenable number.

211688 is a deficient number, since it is larger than the sum of its proper divisors (194392).

211688 is a wasteful number, since it uses less digits than its factorization.

211688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 616 (or 612 counting only the distinct ones).

The product of its digits is 768, while the sum is 26.

The square root of 211688 is about 460.0956422310. The cubic root of 211688 is about 59.5980540782.

The spelling of 211688 in words is "two hundred eleven thousand, six hundred eighty-eight".