211716 has 18 divisors (see below), whose sum is σ = 535262. Its totient is φ = 70560.

The previous prime is 211711. The next prime is 211723. The reversal of 211716 is 617112.

Added to its reverse (617112) it gives a triangular number (828828 = T₁₂₈₇).

It can be written as a sum of positive squares in only one way, i.e., 202500 + 9216 = 450^2 + 96^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (211711) by changing a digit.

211716 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 5 ways as a sum of consecutive naturals, for example, 2905 + ... + 2976.

2²¹¹⁷¹⁶ is an apocalyptic number.

It is an amenable number.

211716 is an abundant number, since it is smaller than the sum of its proper divisors (323546).

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

211716 is a wasteful number, since it uses less digits than its factorization.

211716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5891 (or 5886 counting only the distinct ones).

The product of its digits is 84, while the sum is 18.

The square root of 211716 is about 460.1260696809. The cubic root of 211716 is about 59.6006816432.

Adding to 211716 its reverse (617112), we get a palindrome (828828).

It can be divided in two parts, 2 and 11716, that multiplied together give a palindrome (23432).

The spelling of 211716 in words is "two hundred eleven thousand, seven hundred sixteen".