561216 has 56 divisors (see below), whose sum is σ = 1544320. Its totient is φ = 179712.

The previous prime is 561199. The next prime is 561229. The reversal of 561216 is 612165.

It is a happy number.

It is an alternating number because its digits alternate between odd and even.

It is a junction number, because it is equal to n+sod(n) for n = 561192 and 561201.

It is an unprimeable number.

561216 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 7 ways as a sum of consecutive naturals, for example, 7065 + ... + 7143.

2⁵⁶¹²¹⁶ 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 561216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (772160).

561216 is an abundant number, since it is smaller than the sum of its proper divisors (983104).

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

561216 is a wasteful number, since it uses less digits than its factorization.

561216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131 (or 121 counting only the distinct ones).

The product of its digits is 360, while the sum is 21.

The square root of 561216 is about 749.1435109510. The cubic root of 561216 is about 82.4853233764.

It can be divided in two parts, 561 and 216, that added together give a palindrome (777).

The spelling of 561216 in words is "five hundred sixty-one thousand, two hundred sixteen".