216456 has 32 divisors (see below), whose sum is σ = 561600. Its totient is φ = 69440.

The previous prime is 216451. The next prime is 216481. The reversal of 216456 is 654612.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an Ulam number.

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (216451) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 541 + ... + 851.

It is an arithmetic number, because the mean of its divisors is an integer number (17550).

2²¹⁶⁴⁵⁶ 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 216456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (280800).

216456 is an abundant number, since it is smaller than the sum of its proper divisors (345144).

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

216456 is a wasteful number, since it uses less digits than its factorization.

216456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 349 (or 345 counting only the distinct ones).

The product of its digits is 1440, while the sum is 24.

The square root of 216456 is about 465.2483207922. The cubic root of 216456 is about 60.0421925451.

The spelling of 216456 in words is "two hundred sixteen thousand, four hundred fifty-six".