213656 has 16 divisors (see below), whose sum is σ = 424440. Its totient is φ = 100480.

The previous prime is 213649. The next prime is 213659. The reversal of 213656 is 656312.

213656 = 104² + 105² + ... + 120².

213656 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 a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213659) 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 3 ways as a sum of consecutive naturals, for example, 650 + ... + 921.

2²¹³⁶⁵⁶ is an apocalyptic number.

It is an amenable number.

213656 is a deficient number, since it is larger than the sum of its proper divisors (210784).

213656 is a wasteful number, since it uses less digits than its factorization.

213656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1594 (or 1590 counting only the distinct ones).

The product of its digits is 1080, while the sum is 23.

The square root of 213656 is about 462.2293802865. The cubic root of 213656 is about 59.7821731107.

Adding to 213656 its reverse (656312), we get a palindrome (869968).

The spelling of 213656 in words is "two hundred thirteen thousand, six hundred fifty-six".