217159728016 has 405 divisors, whose sum is σ = 577980648147. Its totient is φ = 78736035840.

The previous prime is 217159728013. The next prime is 217159728029. The reversal of 217159728016 is 610827951712.

The square root of 217159728016 is 466004.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 286963600 + 216872764416 = 16940^2 + 465696^2 .

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (217159728013) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 2439996900 + ... + 2439996988.

Almost surely, 2^217159728016 is an apocalyptic number.

217159728016 is the 466004-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 217159728016

217159728016 is an abundant number, since it is smaller than the sum of its proper divisors (360820920131).

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

217159728016 is a wasteful number, since it uses less digits than its factorization.

217159728016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 256 (or 126 counting only the distinct ones).

The product of its (nonzero) digits is 423360, while the sum is 49.

Multiplying 217159728016 by its sum of digits (49), we get a square (10640826672784 = 3262028²).

217159728016 divided by its sum of digits (49) gives a square (4431831184 = 66572²).

The spelling of 217159728016 in words is "two hundred seventeen billion, one hundred fifty-nine million, seven hundred twenty-eight thousand, sixteen".