216171728 has 20 divisors (see below), whose sum is σ = 443470500. Its totient is φ = 101727744.

The previous prime is 216171727. The next prime is 216171817. The reversal of 216171728 is 827171612.

It can be written as a sum of positive squares in 2 ways, for example, as 151979584 + 64192144 = 12328^2 + 8012^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216171727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 397103 + ... + 397646.

It is an arithmetic number, because the mean of its divisors is an integer number (22173525).

Almost surely, 2^216171728 is an apocalyptic number.

It is an amenable number.

216171728 is an abundant number, since it is smaller than the sum of its proper divisors (227298772).

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

216171728 is a wasteful number, since it uses less digits than its factorization.

216171728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 794774 (or 794768 counting only the distinct ones).

The product of its digits is 9408, while the sum is 35.

The square root of 216171728 is about 14702.7796011503. The cubic root of 216171728 is about 600.1589652871.

The spelling of 216171728 in words is "two hundred sixteen million, one hundred seventy-one thousand, seven hundred twenty-eight".