3521 has 4 divisors (see below), whose sum is σ = 4032. Its totient is φ = 3012.

The previous prime is 3517. The next prime is 3527. The reversal of 3521 is 1253.

3521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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: 1253 = 7 ⋅179.

It is a cyclic number.

It is not a de Polignac number, because 3521 - 2² = 3517 is a prime.

It is a Curzon number.

It is a plaindrome in base 13.

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (3527) 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, 245 + ... + 258.

It is an arithmetic number, because the mean of its divisors is an integer number (1008).

It is a Proth number, since it is equal to 55 ⋅ 2⁶ + 1 and 55 < 2⁶.

2³⁵²¹ is an apocalyptic number.

It is an amenable number.

3521 is a deficient number, since it is larger than the sum of its proper divisors (511).

3521 is an equidigital number, since it uses as much as digits as its factorization.

3521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510.

The product of its digits is 30, while the sum is 11.

The square root of 3521 is about 59.3380147966. The cubic root of 3521 is about 15.2132502190.

Adding to 3521 its reverse (1253), we get a palindrome (4774).

It can be divided in two parts, 352 and 1, that added together give a palindrome (353).

The spelling of 3521 in words is "three thousand, five hundred twenty-one".