217628560 has 60 divisors (see below), whose sum is σ = 537558228. Its totient is φ = 81922048.

The previous prime is 217628539. The next prime is 217628563. The reversal of 217628560 is 65826712.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 68690944 + 148937616 = 8288^2 + 12204^2 .

It is not an unprimeable number, because it can be changed into a prime (217628563) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18414 + ... + 27826.

Almost surely, 2^217628560 is an apocalyptic number.

217628560 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 217628560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (268779114).

217628560 is an abundant number, since it is smaller than the sum of its proper divisors (319929668).

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

217628560 is a wasteful number, since it uses less digits than its factorization.

217628560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9460 (or 9437 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 217628560 is about 14752.2391520745. The cubic root of 217628560 is about 601.5041519862.

The spelling of 217628560 in words is "two hundred seventeen million, six hundred twenty-eight thousand, five hundred sixty".