628221 has 8 divisors (see below), whose sum is σ = 913824. Its totient is φ = 380720.

The previous prime is 628219. The next prime is 628231. The reversal of 628221 is 122826.

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 628221 - 2¹ = 628219 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (628231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9486 + ... + 9551.

It is an arithmetic number, because the mean of its divisors is an integer number (114228).

2⁶²⁸²²¹ is an apocalyptic number.

It is an amenable number.

628221 is a deficient number, since it is larger than the sum of its proper divisors (285603).

628221 is a wasteful number, since it uses less digits than its factorization.

628221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19051.

The product of its digits is 384, while the sum is 21.

The square root of 628221 is about 792.6039364020. The cubic root of 628221 is about 85.6454212752.

The spelling of 628221 in words is "six hundred twenty-eight thousand, two hundred twenty-one".