217308672 has 120 divisors (see below), whose sum is σ = 716869296. Its totient is φ = 62078976.

The previous prime is 217308649. The next prime is 217308677. The reversal of 217308672 is 276803712.

217308672 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 (217308677) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28888 + ... + 35624.

Almost surely, 2^217308672 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 217308672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (358434648).

217308672 is an abundant number, since it is smaller than the sum of its proper divisors (499560624).

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

217308672 is an equidigital number, since it uses as much as digits as its factorization.

217308672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6768 (or 6749 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 36.

The square root of 217308672 is about 14741.3931499028. The cubic root of 217308672 is about 601.2092943744.

The spelling of 217308672 in words is "two hundred seventeen million, three hundred eight thousand, six hundred seventy-two".