213564 has 36 divisors (see below), whose sum is σ = 551544. Its totient is φ = 63936.

The previous prime is 213557. The next prime is 213589. The reversal of 213564 is 465312.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 213564.

It is a congruent number.

It is an unprimeable number.

213564 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5754 + ... + 5790.

2²¹³⁵⁶⁴ 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 213564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (275772).

213564 is an abundant number, since it is smaller than the sum of its proper divisors (337980).

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

213564 is a wasteful number, since it uses less digits than its factorization.

213564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94 (or 55 counting only the distinct ones).

The product of its digits is 720, while the sum is 21.

The square root of 213564 is about 462.1298518815. The cubic root of 213564 is about 59.7735911698.

Multiplying 213564 by its sum of digits (21), we get a palindrome (4484844).

Adding to 213564 its reverse (465312), we get a palindrome (678876).

It can be divided in two parts, 213 and 564, that added together give a palindrome (777).

The spelling of 213564 in words is "two hundred thirteen thousand, five hundred sixty-four".