221217609 has 8 divisors (see below), whose sum is σ = 299956320. Its totient is φ = 144978656.

The previous prime is 221217593. The next prime is 221217613. The reversal of 221217609 is 906712122.

221217609 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 221217609 - 2⁴ = 221217593 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (221217649) 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, 624732 + ... + 625085.

It is an arithmetic number, because the mean of its divisors is an integer number (37494540).

Almost surely, 2^221217609 is an apocalyptic number.

It is an amenable number.

221217609 is a deficient number, since it is larger than the sum of its proper divisors (78738711).

221217609 is a wasteful number, since it uses less digits than its factorization.

221217609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1249879.

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 221217609 is about 14873.3859292362. The cubic root of 221217609 is about 604.7927336819.

The spelling of 221217609 in words is "two hundred twenty-one million, two hundred seventeen thousand, six hundred nine".