217681568 has 48 divisors (see below), whose sum is σ = 481614336. Its totient is φ = 96096000.

The previous prime is 217681567. The next prime is 217681579. The reversal of 217681568 is 865186712.

It is a happy number.

217681568 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (217681567) 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, 1808 + ... + 20943.

It is an arithmetic number, because the mean of its divisors is an integer number (10033632).

Almost surely, 2^217681568 is an apocalyptic number.

It is an amenable number.

217681568 is an abundant number, since it is smaller than the sum of its proper divisors (263932768).

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

217681568 is a wasteful number, since it uses less digits than its factorization.

217681568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22797 (or 22789 counting only the distinct ones).

The product of its digits is 161280, while the sum is 44.

The square root of 217681568 is about 14754.0356513057. The cubic root of 217681568 is about 601.5529843388.

The spelling of 217681568 in words is "two hundred seventeen million, six hundred eighty-one thousand, five hundred sixty-eight".