1608221 has 4 divisors (see below), whose sum is σ = 1630944. Its totient is φ = 1585500.

The previous prime is 1608209. The next prime is 1608227. The reversal of 1608221 is 1228061.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1228061 = 223 ⋅5507.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1608221 is a prime.

It is a super-3 number, since 3×1608221³ = 12478386728555333583, which contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1608193 and 1608202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1608227) 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, 11255 + ... + 11396.

It is an arithmetic number, because the mean of its divisors is an integer number (407736).

2^1608221 is an apocalyptic number.

It is an amenable number.

1608221 is a deficient number, since it is larger than the sum of its proper divisors (22723).

1608221 is an equidigital number, since it uses as much as digits as its factorization.

1608221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22722.

The product of its (nonzero) digits is 192, while the sum is 20.

The square root of 1608221 is about 1268.1565360790. The cubic root of 1608221 is about 117.1606869974.

The spelling of 1608221 in words is "one million, six hundred eight thousand, two hundred twenty-one".