3553221 has 32 divisors (see below), whose sum is σ = 5909760. Its totient is φ = 1852416.

The previous prime is 3553217. The next prime is 3553223. The reversal of 3553221 is 1223553.

It is not a de Polignac number, because 3553221 - 2² = 3553217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a d-powerful number, because it can be written as 3³ + 5⁴ + 5⁹ + 3¹³ + 2¹⁰ + 2¹² + 1 .

It is a Curzon number.

3553221 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3553223) 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 31 ways as a sum of consecutive naturals, for example, 13075 + ... + 13343.

It is an arithmetic number, because the mean of its divisors is an integer number (184680).

Almost surely, 2^3553221 is an apocalyptic number.

It is an amenable number.

3553221 is a deficient number, since it is larger than the sum of its proper divisors (2356539).

3553221 is a wasteful number, since it uses less digits than its factorization.

3553221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333.

The product of its digits is 900, while the sum is 21.

The square root of 3553221 is about 1884.9989389917. The cubic root of 3553221 is about 152.5951533725.

Adding to 3553221 its reverse (1223553), we get a palindrome (4776774).

It can be divided in two parts, 35532 and 21, that added together give a palindrome (35553).

The spelling of 3553221 in words is "three million, five hundred fifty-three thousand, two hundred twenty-one".