213811 has 4 divisors (see below), whose sum is σ = 230272. Its totient is φ = 197352.

The previous prime is 213799. The next prime is 213821. The reversal of 213811 is 118312.

213811 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.

It is a cyclic number.

It is not a de Polignac number, because 213811 - 2¹³ = 205619 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (213821) 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, 8211 + ... + 8236.

It is an arithmetic number, because the mean of its divisors is an integer number (57568).

2²¹³⁸¹¹ is an apocalyptic number.

213811 is a deficient number, since it is larger than the sum of its proper divisors (16461).

213811 is a wasteful number, since it uses less digits than its factorization.

213811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16460.

The product of its digits is 48, while the sum is 16.

The square root of 213811 is about 462.3970155613. The cubic root of 213811 is about 59.7966262456.

It can be divided in two parts, 213 and 811, that added together give a 10-th power (1024 = 2¹⁰).

The spelling of 213811 in words is "two hundred thirteen thousand, eight hundred eleven".