84217728 has 256 divisors, whose sum is σ = 287884800. Its totient is φ = 21233664.

The previous prime is 84217717. The next prime is 84217729. The reversal of 84217728 is 82771248.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (84217729) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 868176 + ... + 868272.

It is an arithmetic number, because the mean of its divisors is an integer number (1124550).

Almost surely, 2^84217728 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 84217728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143942400).

84217728 is an abundant number, since it is smaller than the sum of its proper divisors (203667072).

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

84217728 is a wasteful number, since it uses less digits than its factorization.

84217728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157 (or 145 counting only the distinct ones).

The product of its digits is 50176, while the sum is 39.

The square root of 84217728 is about 9177.0217391047. The cubic root of 84217728 is about 438.3299779831.

The spelling of 84217728 in words is "eighty-four million, two hundred seventeen thousand, seven hundred twenty-eight".