4571221 has 4 divisors (see below), whose sum is σ = 4578444. Its totient is φ = 4564000.

The previous prime is 4571219. The next prime is 4571233. The reversal of 4571221 is 1221754.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1221754 = 2 ⋅610877.

It can be written as a sum of positive squares in 2 ways, for example, as 4100625 + 470596 = 2025^2 + 686^2 .

It is a cyclic number.

It is not a de Polignac number, because 4571221 - 2¹ = 4571219 is a prime.

It is a super-2 number, since 2×4571221² = 41792122861682, which contains 22 as substring.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

4571221 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 4571192 and 4571201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4571251) 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, 2560 + ... + 3961.

It is an arithmetic number, because the mean of its divisors is an integer number (1144611).

Almost surely, 2^4571221 is an apocalyptic number.

It is an amenable number.

4571221 is a deficient number, since it is larger than the sum of its proper divisors (7223).

4571221 is an equidigital number, since it uses as much as digits as its factorization.

4571221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7222.

The product of its digits is 560, while the sum is 22.

The square root of 4571221 is about 2138.0413934253. The cubic root of 4571221 is about 165.9627946812.

Adding to 4571221 its reverse (1221754), we get a palindrome (5792975).

The spelling of 4571221 in words is "four million, five hundred seventy-one thousand, two hundred twenty-one".