211993 has 4 divisors (see below), whose sum is σ = 213120. Its totient is φ = 210868.

The previous prime is 211979. The next prime is 211997. The reversal of 211993 is 399112.

211993 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (211997) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 205 + ... + 682.

It is an arithmetic number, because the mean of its divisors is an integer number (53280).

2²¹¹⁹⁹³ is an apocalyptic number.

It is an amenable number.

211993 is a deficient number, since it is larger than the sum of its proper divisors (1127).

211993 is an equidigital number, since it uses as much as digits as its factorization.

211993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1126.

The product of its digits is 486, while the sum is 25.

The square root of 211993 is about 460.4269757519. The cubic root of 211993 is about 59.6266632947.

The spelling of 211993 in words is "two hundred eleven thousand, nine hundred ninety-three".