3221531 has 4 divisors (see below), whose sum is σ = 3252912. Its totient is φ = 3190152.

The previous prime is 3221513. The next prime is 3221539. The reversal of 3221531 is 1351223.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3221531 is a prime.

It is a super-2 number, since 2×3221531² = 20756523967922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3221539) 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, 15536 + ... + 15741.

It is an arithmetic number, because the mean of its divisors is an integer number (813228).

Almost surely, 2^3221531 is an apocalyptic number.

3221531 is a deficient number, since it is larger than the sum of its proper divisors (31381).

3221531 is a wasteful number, since it uses less digits than its factorization.

3221531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31380.

The product of its digits is 180, while the sum is 17.

The square root of 3221531 is about 1794.8623902684. The cubic root of 3221531 is about 147.6910251221.

Adding to 3221531 its reverse (1351223), we get a palindrome (4572754).

The spelling of 3221531 in words is "three million, two hundred twenty-one thousand, five hundred thirty-one".