217428120 has 192 divisors, whose sum is σ = 869843520. Its totient is φ = 45868032.

The previous prime is 217428089. The next prime is 217428121. The reversal of 217428120 is 21824712.

217428120 is a `hidden beast` number, since 217 + 428 + 1 + 20 = 666.

217428120 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×217428120³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217428121) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 29442 + ... + 36078.

It is an arithmetic number, because the mean of its divisors is an integer number (4530435).

Almost surely, 2^217428120 is an apocalyptic number.

217428120 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 217428120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (434921760).

217428120 is an abundant number, since it is smaller than the sum of its proper divisors (652415400).

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

217428120 is a wasteful number, since it uses less digits than its factorization.

217428120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6674 (or 6667 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 217428120 is about 14745.4440421440. Note that the first 3 decimals coincide. The cubic root of 217428120 is about 601.3194297152.

The spelling of 217428120 in words is "two hundred seventeen million, four hundred twenty-eight thousand, one hundred twenty".