3520221 has 4 divisors (see below), whose sum is σ = 4693632. Its totient is φ = 2346812.

The previous prime is 3520211. The next prime is 3520229. The reversal of 3520221 is 1220253.

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.

It is a cyclic number.

It is not a de Polignac number, because 3520221 - 2⁶ = 3520157 is a prime.

It is a D-number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 3520221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3520229) 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, 586701 + ... + 586706.

It is an arithmetic number, because the mean of its divisors is an integer number (1173408).

Almost surely, 2^3520221 is an apocalyptic number.

It is an amenable number.

3520221 is a deficient number, since it is larger than the sum of its proper divisors (1173411).

3520221 is a wasteful number, since it uses less digits than its factorization.

3520221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1173410.

The product of its (nonzero) digits is 120, while the sum is 15.

The square root of 3520221 is about 1876.2251997029. The cubic root of 3520221 is about 152.1212818960.

Adding to 3520221 its reverse (1220253), we get a palindrome (4740474).

Subtracting from 3520221 its reverse (1220253), we obtain a cube (2299968 = 132³).

It can be divided in two parts, 3520 and 221, that added together give a triangular number (3741 = T₈₆).

The spelling of 3520221 in words is "three million, five hundred twenty thousand, two hundred twenty-one".