211906 has 4 divisors (see below), whose sum is σ = 317862. Its totient is φ = 105952.

The previous prime is 211891. The next prime is 211927. The reversal of 211906 is 609112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 210681 + 1225 = 459^2 + 35^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 52975 + ... + 52978.

2²¹¹⁹⁰⁶ is an apocalyptic number.

211906 is a deficient number, since it is larger than the sum of its proper divisors (105956).

211906 is a wasteful number, since it uses less digits than its factorization.

211906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105955.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 211906 is about 460.3324885341. The cubic root of 211906 is about 59.6185054318.

The spelling of 211906 in words is "two hundred eleven thousand, nine hundred six".