3131204221 has 2 divisors, whose sum is σ = 3131204222. Its totient is φ = 3131204220.

The previous prime is 3131204147. The next prime is 3131204233. The reversal of 3131204221 is 1224021313.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2646588025 + 484616196 = 51445^2 + 22014^2 .

It is a cyclic number.

It is not a de Polignac number, because 3131204221 - 2¹⁵ = 3131171453 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3131205221) 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, 1565602110 + 1565602111.

It is an arithmetic number, because the mean of its divisors is an integer number (1565602111).

Almost surely, 2^3131204221 is an apocalyptic number.

It is an amenable number.

3131204221 is a deficient number, since it is larger than the sum of its proper divisors (1).

3131204221 is an equidigital number, since it uses as much as digits as its factorization.

3131204221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 3131204221 is about 55957.1641615263. The cubic root of 3131204221 is about 1462.9757629676.

Adding to 3131204221 its reverse (1224021313), we get a palindrome (4355225534).

The spelling of 3131204221 in words is "three billion, one hundred thirty-one million, two hundred four thousand, two hundred twenty-one".