217382928 has 80 divisors (see below), whose sum is σ = 644720640. Its totient is φ = 61826688.

The previous prime is 217382923. The next prime is 217382939. The reversal of 217382928 is 829283712.

It is a happy number.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 217382928.

It is not an unprimeable number, because it can be changed into a prime (217382923) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78951 + ... + 81657.

It is an arithmetic number, because the mean of its divisors is an integer number (8059008).

Almost surely, 2^217382928 is an apocalyptic number.

217382928 is a gapful number since it is divisible by the number (28) 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 217382928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (322360320).

217382928 is an abundant number, since it is smaller than the sum of its proper divisors (427337712).

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

217382928 is a wasteful number, since it uses less digits than its factorization.

217382928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2964 (or 2958 counting only the distinct ones).

The product of its digits is 96768, while the sum is 42.

The square root of 217382928 is about 14743.9115569784. The cubic root of 217382928 is about 601.2777658148.

The spelling of 217382928 in words is "two hundred seventeen million, three hundred eighty-two thousand, nine hundred twenty-eight".