6623221 has 4 divisors (see below), whose sum is σ = 7225344. Its totient is φ = 6021100.

The previous prime is 6623213. The next prime is 6623231. The reversal of 6623221 is 1223266.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6623221 - 2³ = 6623213 is a prime.

It is a Duffinian number.

6623221 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 6623192 and 6623201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6623231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 301045 + ... + 301066.

It is an arithmetic number, because the mean of its divisors is an integer number (1806336).

Almost surely, 2^6623221 is an apocalyptic number.

It is an amenable number.

6623221 is a deficient number, since it is larger than the sum of its proper divisors (602123).

6623221 is a wasteful number, since it uses less digits than its factorization.

6623221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 602122.

The product of its digits is 864, while the sum is 22.

The square root of 6623221 is about 2573.5619285341. The cubic root of 6623221 is about 187.7974750555.

Adding to 6623221 its reverse (1223266), we get a palindrome (7846487).

It can be divided in two parts, 662 and 3221, that added together give a palindrome (3883).

The spelling of 6623221 in words is "six million, six hundred twenty-three thousand, two hundred twenty-one".