211804 has 6 divisors (see below), whose sum is σ = 370664. Its totient is φ = 105900.

The previous prime is 211801. The next prime is 211811. The reversal of 211804 is 408112.

It is a happy number.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26472 + ... + 26479.

2²¹¹⁸⁰⁴ is an apocalyptic number.

It is an amenable number.

211804 is a deficient number, since it is larger than the sum of its proper divisors (158860).

211804 is a wasteful number, since it uses less digits than its factorization.

211804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52955 (or 52953 counting only the distinct ones).

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

The square root of 211804 is about 460.2216857124. The cubic root of 211804 is about 59.6089381967.

Adding to 211804 its reverse (408112), we get a palindrome (619916).

The spelling of 211804 in words is "two hundred eleven thousand, eight hundred four".