16600221 has 40 divisors (see below), whose sum is σ = 27971328. Its totient is φ = 9720000.

The previous prime is 16600217. The next prime is 16600229. The reversal of 16600221 is 12200661.

It is a happy number.

16600221 is a `hidden beast` number, since 1 + 660 + 0 + 2 + 2 + 1 = 666.

It is not a de Polignac number, because 16600221 - 2² = 16600217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16600194 and 16600203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16600229) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 27321 + ... + 27921.

Almost surely, 2^16600221 is an apocalyptic number.

16600221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16600221 is a deficient number, since it is larger than the sum of its proper divisors (11371107).

16600221 is a wasteful number, since it uses less digits than its factorization.

16600221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 655 (or 646 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 16600221 is about 4074.3368785607. The cubic root of 16600221 is about 255.0965724185.

Adding to 16600221 its reverse (12200661), we get a palindrome (28800882).

The spelling of 16600221 in words is "sixteen million, six hundred thousand, two hundred twenty-one".