215556 has 48 divisors (see below), whose sum is σ = 580608. Its totient is φ = 61600.

The previous prime is 215531. The next prime is 215563. The reversal of 215556 is 655512.

215556 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 215556.

It is an unprimeable number.

215556 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 15 ways as a sum of consecutive naturals, for example, 3001 + ... + 3071.

It is an arithmetic number, because the mean of its divisors is an integer number (12096).

215556 is a Friedman number, since it can be written as (5+2^6)*(5^5-1), using all its digits and the basic arithmetic operations.

2²¹⁵⁵⁵⁶ 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 215556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (290304).

215556 is an abundant number, since it is smaller than the sum of its proper divisors (365052).

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

215556 is a wasteful number, since it uses less digits than its factorization.

215556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112 (or 110 counting only the distinct ones).

The product of its digits is 1500, while the sum is 24.

The square root of 215556 is about 464.2800878780. The cubic root of 215556 is about 59.9588606880.

It can be divided in two parts, 2155 and 56, that added together give a triangular number (2211 = T₆₆).

The spelling of 215556 in words is "two hundred fifteen thousand, five hundred fifty-six".