211965 has 16 divisors (see below), whose sum is σ = 365568. Its totient is φ = 104256.

The previous prime is 211949. The next prime is 211969. The reversal of 211965 is 569112.

It is not a de Polignac number, because 211965 - 2⁴ = 211949 is a prime.

It is a super-2 number, since 2×211965² = 89858322450, which contains 22 as substring.

It is a Curzon number.

211965 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211969) 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, 349 + ... + 738.

It is an arithmetic number, because the mean of its divisors is an integer number (22848).

2²¹¹⁹⁶⁵ is an apocalyptic number.

It is an amenable number.

211965 is a deficient number, since it is larger than the sum of its proper divisors (153603).

211965 is a wasteful number, since it uses less digits than its factorization.

211965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1108.

The product of its digits is 540, while the sum is 24.

The square root of 211965 is about 460.3965681888. The cubic root of 211965 is about 59.6240380192.

It can be divided in two parts, 211 and 965, that added together give a triangular number (1176 = T₄₈).

The spelling of 211965 in words is "two hundred eleven thousand, nine hundred sixty-five".