213644 has 6 divisors (see below), whose sum is σ = 373884. Its totient is φ = 106820.

The previous prime is 213641. The next prime is 213649. The reversal of 213644 is 446312.

It is a happy number.

213644 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (213641) 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 as a sum of consecutive naturals, namely, 26702 + ... + 26709.

It is an arithmetic number, because the mean of its divisors is an integer number (62314).

2²¹³⁶⁴⁴ is an apocalyptic number.

It is an amenable number.

213644 is a deficient number, since it is larger than the sum of its proper divisors (160240).

213644 is a wasteful number, since it uses less digits than its factorization.

213644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53415 (or 53413 counting only the distinct ones).

The product of its digits is 576, while the sum is 20.

The square root of 213644 is about 462.2163995360. The cubic root of 213644 is about 59.7810538669.

Adding to 213644 its reverse (446312), we get a palindrome (659956).

The spelling of 213644 in words is "two hundred thirteen thousand, six hundred forty-four".