216218628 has 18 divisors (see below), whose sum is σ = 546552734. Its totient is φ = 72072864.

The previous prime is 216218623. The next prime is 216218669. The reversal of 216218628 is 826812612.

216218628 is a `hidden beast` number, since 2 + 1 + 6 + 21 + 8 + 628 = 666.

It can be written as a sum of positive squares in only one way, i.e., 212226624 + 3992004 = 14568^2 + 1998^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 6006073 = 216218628 / (2 + 1 + 6 + 2 + 1 + 8 + 6 + 2 + 8).

It is a junction number, because it is equal to n+sod(n) for n = 216218592 and 216218601.

It is not an unprimeable number, because it can be changed into a prime (216218621) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3003001 + ... + 3003072.

Almost surely, 2^216218628 is an apocalyptic number.

It is an amenable number.

216218628 is an abundant number, since it is smaller than the sum of its proper divisors (330334106).

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

216218628 is a wasteful number, since it uses less digits than its factorization.

216218628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6006083 (or 6006078 counting only the distinct ones).

The product of its digits is 18432, while the sum is 36.

The square root of 216218628 is about 14704.3744511625. The cubic root of 216218628 is about 600.2023650730.

The spelling of 216218628 in words is "two hundred sixteen million, two hundred eighteen thousand, six hundred twenty-eight".