220728617 has 4 divisors (see below), whose sum is σ = 224469840. Its totient is φ = 216987396.

The previous prime is 220728601. The next prime is 220728661. The reversal of 220728617 is 716827022.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 220728617 - 2⁴ = 220728601 is a prime.

It is a super-3 number, since 3×220728617³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (220728817) 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, 1870523 + ... + 1870640.

It is an arithmetic number, because the mean of its divisors is an integer number (56117460).

Almost surely, 2^220728617 is an apocalyptic number.

It is an amenable number.

220728617 is a deficient number, since it is larger than the sum of its proper divisors (3741223).

220728617 is an equidigital number, since it uses as much as digits as its factorization.

220728617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3741222.

The product of its (nonzero) digits is 18816, while the sum is 35.

The square root of 220728617 is about 14856.9383454331. The cubic root of 220728617 is about 604.3467821688.

The spelling of 220728617 in words is "two hundred twenty million, seven hundred twenty-eight thousand, six hundred seventeen".