211664 has 10 divisors (see below), whose sum is σ = 410130. Its totient is φ = 105824.

The previous prime is 211663. The next prime is 211681. The reversal of 211664 is 466112.

It is a happy number.

211664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 211600 + 64 = 460^2 + 8^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6599 + ... + 6630.

It is an arithmetic number, because the mean of its divisors is an integer number (41013).

2²¹¹⁶⁶⁴ is an apocalyptic number.

It is an amenable number.

211664 is a deficient number, since it is larger than the sum of its proper divisors (198466).

211664 is a wasteful number, since it uses less digits than its factorization.

211664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13237 (or 13231 counting only the distinct ones).

The product of its digits is 288, while the sum is 20.

The square root of 211664 is about 460.0695599581. The cubic root of 211664 is about 59.5958016952.

Adding to 211664 its reverse (466112), we get a palindrome (677776).

It can be divided in two parts, 2116 and 64, that multiplied together give a square (135424 = 368²).

The spelling of 211664 in words is "two hundred eleven thousand, six hundred sixty-four".