3216131221 has 2 divisors, whose sum is σ = 3216131222. Its totient is φ = 3216131220.

The previous prime is 3216131209. The next prime is 3216131249. The reversal of 3216131221 is 1221316123.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2351183121 + 864948100 = 48489^2 + 29410^2 .

It is a cyclic number.

It is not a de Polignac number, because 3216131221 - 2¹⁷ = 3216000149 is a prime.

It is a super-5 number, since 5×3216131221⁵ (a number of 49 digits) contains 55555 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 3216131192 and 3216131201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3216131251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1608065610 + 1608065611.

It is an arithmetic number, because the mean of its divisors is an integer number (1608065611).

Almost surely, 2^3216131221 is an apocalyptic number.

It is an amenable number.

3216131221 is a deficient number, since it is larger than the sum of its proper divisors (1).

3216131221 is an equidigital number, since it uses as much as digits as its factorization.

3216131221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432, while the sum is 22.

The square root of 3216131221 is about 56710.9444551931. The cubic root of 3216131221 is about 1476.0846138788.

Adding to 3216131221 its reverse (1221316123), we get a palindrome (4437447344).

The spelling of 3216131221 in words is "three billion, two hundred sixteen million, one hundred thirty-one thousand, two hundred twenty-one".