217164672 has 128 divisors (see below), whose sum is σ = 661939200. Its totient is φ = 70018560.

The previous prime is 217164611. The next prime is 217164679. The reversal of 217164672 is 276461712.

217164672 is a `hidden beast` number, since 2 + 1 + 7 + 1 + 646 + 7 + 2 = 666.

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

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 (217164679) 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, 106123 + ... + 108149.

It is an arithmetic number, because the mean of its divisors is an integer number (5171400).

Almost surely, 2^217164672 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 217164672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (330969600).

217164672 is an abundant number, since it is smaller than the sum of its proper divisors (444774528).

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

217164672 is a wasteful number, since it uses less digits than its factorization.

217164672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2081 (or 2063 counting only the distinct ones).

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

The square root of 217164672 is about 14736.5081345616. The cubic root of 217164672 is about 601.0764675411.

The spelling of 217164672 in words is "two hundred seventeen million, one hundred sixty-four thousand, six hundred seventy-two".