217680516 has 27 divisors (see below), whose sum is σ = 550471831. Its totient is φ = 72530664.

The previous prime is 217680433. The next prime is 217680523. The reversal of 217680516 is 615086712.

The square root of 217680516 is 14754.

It is a perfect power (a square), and thus also a powerful number.

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

It is a Duffinian number.

It is an unprimeable number.

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 8 ways as a sum of consecutive naturals, for example, 87295 + ... + 89753.

Almost surely, 2^217680516 is an apocalyptic number.

217680516 is the 14754-th square number.

It is an amenable number.

217680516 is an abundant number, since it is smaller than the sum of its proper divisors (332791315).

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

217680516 is an equidigital number, since it uses as much as digits as its factorization.

217680516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4928 (or 2464 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The cubic root of 217680516 is about 601.5520152861.

Multiplying 217680516 by its sum of digits (36), we get a square (7836498576 = 88524²).

217680516 divided by its sum of digits (36) gives a square (6046681 = 2459²).

The spelling of 217680516 in words is "two hundred seventeen million, six hundred eighty thousand, five hundred sixteen".