3216581 has 2 divisors, whose sum is σ = 3216582. Its totient is φ = 3216580.

The previous prime is 3216571. The next prime is 3216583. The reversal of 3216581 is 1856123.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3094081 + 122500 = 1759^2 + 350^2 .

It is a cyclic number.

It is not a de Polignac number, because 3216581 - 2¹⁸ = 2954437 is a prime.

It is a super-2 number, since 2×3216581² = 20692786659122, which contains 22 as substring.

Together with 3216583, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 3216581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3216583) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1608290 + 1608291.

It is an arithmetic number, because the mean of its divisors is an integer number (1608291).

Almost surely, 2^3216581 is an apocalyptic number.

It is an amenable number.

3216581 is a deficient number, since it is larger than the sum of its proper divisors (1).

3216581 is an equidigital number, since it uses as much as digits as its factorization.

3216581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 26.

The square root of 3216581 is about 1793.4829243681. The cubic root of 3216581 is about 147.6153421282.

The spelling of 3216581 in words is "three million, two hundred sixteen thousand, five hundred eighty-one".