211840 has 32 divisors (see below), whose sum is σ = 507960. Its totient is φ = 84480.

The previous prime is 211817. The next prime is 211859. The reversal of 211840 is 48112.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (32).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is an unprimeable number.

211840 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, 475 + ... + 805.

2²¹¹⁸⁴⁰ is an apocalyptic number.

211840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 211840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (253980).

211840 is an abundant number, since it is smaller than the sum of its proper divisors (296120).

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

211840 is an equidigital number, since it uses as much as digits as its factorization.

211840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350 (or 338 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 211840 is about 460.2607956366. The cubic root of 211840 is about 59.6123152186.

Adding to 211840 its reverse (48112), we get a palindrome (259952).

The spelling of 211840 in words is "two hundred eleven thousand, eight hundred forty".