3221521 has 4 divisors (see below), whose sum is σ = 3290112. Its totient is φ = 3152932.

The previous prime is 3221513. The next prime is 3221539. The reversal of 3221521 is 1251223.

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: 1251223 = 23 ⋅54401.

It is a cyclic number.

It is not a de Polignac number, because 3221521 - 2³ = 3221513 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 3221495 and 3221504.

It is not an unprimeable number, because it can be changed into a prime (3221501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34225 + ... + 34318.

It is an arithmetic number, because the mean of its divisors is an integer number (822528).

Almost surely, 2^3221521 is an apocalyptic number.

It is an amenable number.

3221521 is a deficient number, since it is larger than the sum of its proper divisors (68591).

3221521 is an equidigital number, since it uses as much as digits as its factorization.

3221521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68590.

The product of its digits is 120, while the sum is 16.

The square root of 3221521 is about 1794.8596045374. The cubic root of 3221521 is about 147.6908723054.

Adding to 3221521 its reverse (1251223), we get a palindrome (4472744).

The spelling of 3221521 in words is "three million, two hundred twenty-one thousand, five hundred twenty-one".