3231131221 has 2 divisors, whose sum is σ = 3231131222. Its totient is φ = 3231131220.

The previous prime is 3231131219. The next prime is 3231131237. The reversal of 3231131221 is 1221311323.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2270999025 + 960132196 = 47655^2 + 30986^2 .

It is a cyclic number.

It is not a de Polignac number, because 3231131221 - 2¹ = 3231131219 is a prime.

Together with 3231131219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3231131201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1615565610 + 1615565611.

It is an arithmetic number, because the mean of its divisors is an integer number (1615565611).

Almost surely, 2^3231131221 is an apocalyptic number.

It is an amenable number.

3231131221 is a deficient number, since it is larger than the sum of its proper divisors (1).

3231131221 is an equidigital number, since it uses as much as digits as its factorization.

3231131221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 19.

The square root of 3231131221 is about 56843.0402160194. The cubic root of 3231131221 is about 1478.3758694686.

Adding to 3231131221 its reverse (1221311323), we get a palindrome (4452442544).

The spelling of 3231131221 in words is "three billion, two hundred thirty-one million, one hundred thirty-one thousand, two hundred twenty-one".