217105056 has 96 divisors (see below), whose sum is σ = 723703680. Its totient is φ = 62028288.

The previous prime is 217105051. The next prime is 217105081. The reversal of 217105056 is 650501712.

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

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (217105051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11901 + ... + 23996.

It is an arithmetic number, because the mean of its divisors is an integer number (7538580).

Almost surely, 2^217105056 is an apocalyptic number.

It is an amenable number.

217105056 is an abundant number, since it is smaller than the sum of its proper divisors (506598624).

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

217105056 is a wasteful number, since it uses less digits than its factorization.

217105056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35923 (or 35909 counting only the distinct ones).

The product of its (nonzero) digits is 2100, while the sum is 27.

The square root of 217105056 is about 14734.4852641685. The cubic root of 217105056 is about 601.0214600455.

Adding to 217105056 its reverse (650501712), we get a palindrome (867606768).

The spelling of 217105056 in words is "two hundred seventeen million, one hundred five thousand, fifty-six".