218651616 has 96 divisors (see below), whose sum is σ = 665521920. Its totient is φ = 69708672.

The previous prime is 218651599. The next prime is 218651617. The reversal of 218651616 is 616156812.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×218651616² = 95617058358822912, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218651617) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14371 + ... + 25373.

It is an arithmetic number, because the mean of its divisors is an integer number (6932520).

Almost surely, 2^218651616 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 218651616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (332760960).

218651616 is an abundant number, since it is smaller than the sum of its proper divisors (446870304).

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

218651616 is a wasteful number, since it uses less digits than its factorization.

218651616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11045 (or 11031 counting only the distinct ones).

The product of its digits is 17280, while the sum is 36.

The square root of 218651616 is about 14786.8730974469. The cubic root of 218651616 is about 602.4452212842.

The spelling of 218651616 in words is "two hundred eighteen million, six hundred fifty-one thousand, six hundred sixteen".