217992320 has 256 divisors, whose sum is σ = 678585600. Its totient is φ = 65028096.

The previous prime is 217992227. The next prime is 217992323. The reversal of 217992320 is 23299712.

217992320 is digitally balanced in base 3, 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 (35).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217992323) 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 31 ways as a sum of consecutive naturals, for example, 1106462 + ... + 1106658.

It is an arithmetic number, because the mean of its divisors is an integer number (2650725).

Almost surely, 2^217992320 is an apocalyptic number.

217992320 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 217992320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (339292800).

217992320 is an abundant number, since it is smaller than the sum of its proper divisors (460593280).

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

217992320 is a wasteful number, since it uses less digits than its factorization.

217992320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255 (or 243 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 217992320 is about 14764.5629803256. The cubic root of 217992320 is about 601.8390978463.

The spelling of 217992320 in words is "two hundred seventeen million, nine hundred ninety-two thousand, three hundred twenty".