211640 has 64 divisors (see below), whose sum is σ = 574560. Its totient is φ = 69120.

The previous prime is 211639. The next prime is 211643. The reversal of 211640 is 46112.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5702 + ... + 5738.

2²¹¹⁶⁴⁰ is an apocalyptic number.

211640 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 211640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (287280).

211640 is an abundant number, since it is smaller than the sum of its proper divisors (362920).

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

211640 is a wasteful number, since it uses less digits than its factorization.

211640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72 (or 68 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 211640 is about 460.0434762063. The cubic root of 211640 is about 59.5935491419.

Adding to 211640 its reverse (46112), we get a palindrome (257752).

It can be divided in two parts, 21 and 1640, that added together give a palindrome (1661).

The spelling of 211640 in words is "two hundred eleven thousand, six hundred forty".