213421 has 4 divisors (see below), whose sum is σ = 229852. Its totient is φ = 196992.

The previous prime is 213407. The next prime is 213449. The reversal of 213421 is 124312.

213421 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 can be written as a sum of positive squares in 2 ways, for example, as 42025 + 171396 = 205^2 + 414^2 .

It is a cyclic number.

It is not a de Polignac number, because 213421 - 2⁹ = 212909 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 16417 = 213421 / (2 + 1 + 3 + 4 + 2 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213461) 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, 8196 + ... + 8221.

It is an arithmetic number, because the mean of its divisors is an integer number (57463).

2²¹³⁴²¹ is an apocalyptic number.

It is an amenable number.

213421 is a deficient number, since it is larger than the sum of its proper divisors (16431).

213421 is a wasteful number, since it uses less digits than its factorization.

213421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16430.

The product of its digits is 48, while the sum is 13.

The square root of 213421 is about 461.9751075545. The cubic root of 213421 is about 59.7602469544.

Adding to 213421 its reverse (124312), we get a palindrome (337733).

The spelling of 213421 in words is "two hundred thirteen thousand, four hundred twenty-one".