16560221 has 8 divisors (see below), whose sum is σ = 16982784. Its totient is φ = 16141840.

The previous prime is 16560211. The next prime is 16560239. The reversal of 16560221 is 12206561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16560221 - 2¹⁰ = 16559197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16560211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7916 + ... + 9786.

It is an arithmetic number, because the mean of its divisors is an integer number (2122848).

Almost surely, 2^16560221 is an apocalyptic number.

It is an amenable number.

16560221 is a deficient number, since it is larger than the sum of its proper divisors (422563).

16560221 is a wasteful number, since it uses less digits than its factorization.

16560221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2091.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 16560221 is about 4069.4251436782. The cubic root of 16560221 is about 254.8915135089.

Adding to 16560221 its reverse (12206561), we get a palindrome (28766782).

The spelling of 16560221 in words is "sixteen million, five hundred sixty thousand, two hundred twenty-one".