213456 has 20 divisors (see below), whose sum is σ = 551552. Its totient is φ = 71136.

The previous prime is 213449. The next prime is 213461. The reversal of 213456 is 654312.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

213456 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 3 ways as a sum of consecutive naturals, for example, 2176 + ... + 2271.

2²¹³⁴⁵⁶ is an apocalyptic number.

It is an amenable number.

213456 is an abundant number, since it is smaller than the sum of its proper divisors (338096).

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

213456 is a wasteful number, since it uses less digits than its factorization.

213456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4458 (or 4452 counting only the distinct ones).

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

The square root of 213456 is about 462.0129868305. The cubic root of 213456 is about 59.7635135719.

Adding to 213456 its reverse (654312), we get a palindrome (867768).

The spelling of 213456 in words is "two hundred thirteen thousand, four hundred fifty-six".