216616 has 8 divisors (see below), whose sum is σ = 406170. Its totient is φ = 108304.

The previous prime is 216607. The next prime is 216617. The reversal of 216616 is 616612.

It can be written as a sum of positive squares in only one way, i.e., 152100 + 64516 = 390^2 + 254^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (216617) by changing a digit.

216616 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 as a sum of consecutive naturals, namely, 13531 + ... + 13546.

2²¹⁶⁶¹⁶ is an apocalyptic number.

It is an amenable number.

216616 is a deficient number, since it is larger than the sum of its proper divisors (189554).

216616 is a wasteful number, since it uses less digits than its factorization.

216616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27083 (or 27079 counting only the distinct ones).

The product of its digits is 432, while the sum is 22.

The square root of 216616 is about 465.4202402131. The cubic root of 216616 is about 60.0569829024.

The spelling of 216616 in words is "two hundred sixteen thousand, six hundred sixteen".