16624221 has 32 divisors (see below), whose sum is σ = 24624000. Its totient is φ = 9934848.

The previous prime is 16624219. The next prime is 16624243. The reversal of 16624221 is 12242661.

It is not a de Polignac number, because 16624221 - 2¹ = 16624219 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 16624191 and 16624200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16624271) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 147061 + ... + 147173.

It is an arithmetic number, because the mean of its divisors is an integer number (769500).

Almost surely, 2^16624221 is an apocalyptic number.

It is an amenable number.

16624221 is a deficient number, since it is larger than the sum of its proper divisors (7999779).

16624221 is a wasteful number, since it uses less digits than its factorization.

16624221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253.

The product of its digits is 1152, while the sum is 24.

The square root of 16624221 is about 4077.2810793469. The cubic root of 16624221 is about 255.2194496908.

Adding to 16624221 its reverse (12242661), we get a palindrome (28866882).

The spelling of 16624221 in words is "sixteen million, six hundred twenty-four thousand, two hundred twenty-one".