16623321 has 16 divisors (see below), whose sum is σ = 26040000. Its totient is φ = 9299520.

The previous prime is 16623311. The next prime is 16623337. The reversal of 16623321 is 12332661.

It is a happy number.

It is not a de Polignac number, because 16623321 - 2¹⁰ = 16622297 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16623291 and 16623300.

It is not an unprimeable number, because it can be changed into a prime (16623311) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18946 + ... + 19803.

It is an arithmetic number, because the mean of its divisors is an integer number (1627500).

Almost surely, 2^16623321 is an apocalyptic number.

16623321 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16623321 is a deficient number, since it is larger than the sum of its proper divisors (9416679).

16623321 is a wasteful number, since it uses less digits than its factorization.

16623321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38776.

The product of its digits is 1296, while the sum is 24.

The square root of 16623321 is about 4077.1707101862. The cubic root of 16623321 is about 255.2148439281.

Adding to 16623321 its reverse (12332661), we get a palindrome (28955982).

The spelling of 16623321 in words is "sixteen million, six hundred twenty-three thousand, three hundred twenty-one".