3506221 has 4 divisors (see below), whose sum is σ = 3513244. Its totient is φ = 3499200.

The previous prime is 3506213. The next prime is 3506249. The reversal of 3506221 is 1226053.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2528100 + 978121 = 1590^2 + 989^2 .

It is a 3-Lehmer number, since φ(3506221) divides (3506221-1)³.

It is a cyclic number.

It is not a de Polignac number, because 3506221 - 2³ = 3506213 is a prime.

It is a deceptive number, since it divides R_3506220.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3506201) 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, 2700 + ... + 3781.

It is an arithmetic number, because the mean of its divisors is an integer number (878311).

Almost surely, 2^3506221 is an apocalyptic number.

It is an amenable number.

3506221 is a deficient number, since it is larger than the sum of its proper divisors (7023).

3506221 is an equidigital number, since it uses as much as digits as its factorization.

3506221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7022.

The product of its (nonzero) digits is 360, while the sum is 19.

The square root of 3506221 is about 1872.4905874263. The cubic root of 3506221 is about 151.9193506833.

The spelling of 3506221 in words is "three million, five hundred six thousand, two hundred twenty-one".