217264320 has 336 divisors, whose sum is σ = 920861760. Its totient is φ = 45785088.

The previous prime is 217264303. The next prime is 217264343. The reversal of 217264320 is 23462712.

217264320 is a `hidden beast` number, since 2 + 17 + 2 + 643 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (336).

It is a zygodrome in base 2.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 261666 + ... + 262494.

It is an arithmetic number, because the mean of its divisors is an integer number (2740660).

Almost surely, 2^217264320 is an apocalyptic number.

217264320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 217264320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (460430880).

217264320 is an abundant number, since it is smaller than the sum of its proper divisors (703597440).

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

217264320 is a wasteful number, since it uses less digits than its factorization.

217264320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 872 (or 859 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 217264320 is about 14739.8887377076. Note that the first 3 decimals coincide. The cubic root of 217264320 is about 601.1683899646.

The spelling of 217264320 in words is "two hundred seventeen million, two hundred sixty-four thousand, three hundred twenty".