216688512 has 128 divisors (see below), whose sum is σ = 603187200. Its totient is φ = 68843520.

The previous prime is 216688489. The next prime is 216688517. The reversal of 216688512 is 215886612.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×216688512² = 93907822465548288, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216688517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1297453 + ... + 1297619.

It is an arithmetic number, because the mean of its divisors is an integer number (4712400).

Almost surely, 2^216688512 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 216688512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (301593600).

216688512 is an abundant number, since it is smaller than the sum of its proper divisors (386498688).

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

216688512 is a wasteful number, since it uses less digits than its factorization.

216688512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 324 (or 312 counting only the distinct ones).

The product of its digits is 46080, while the sum is 39.

The square root of 216688512 is about 14720.3434742536. The cubic root of 216688512 is about 600.6368349407.

The spelling of 216688512 in words is "two hundred sixteen million, six hundred eighty-eight thousand, five hundred twelve".