213556 has 24 divisors (see below), whose sum is σ = 443520. Its totient is φ = 88032.

The previous prime is 213553. The next prime is 213557. The reversal of 213556 is 655312.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 681 + ... + 943.

It is an arithmetic number, because the mean of its divisors is an integer number (18480).

2²¹³⁵⁵⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 213556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (221760).

213556 is an abundant number, since it is smaller than the sum of its proper divisors (229964).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

213556 is a wasteful number, since it uses less digits than its factorization.

213556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 303 (or 301 counting only the distinct ones).

The product of its digits is 900, while the sum is 22.

The square root of 213556 is about 462.1211962245. The cubic root of 213556 is about 59.7728447976.

Adding to 213556 its reverse (655312), we get a palindrome (868868).

The spelling of 213556 in words is "two hundred thirteen thousand, five hundred fifty-six".