1312020221 has 2 divisors, whose sum is σ = 1312020222. Its totient is φ = 1312020220.

The previous prime is 1312020173. The next prime is 1312020239. The reversal of 1312020221 is 1220202131.

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., 676728196 + 635292025 = 26014^2 + 25205^2 .

It is a cyclic number.

It is not a de Polignac number, because 1312020221 - 2¹⁰ = 1312019197 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1312020196 and 1312020205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1312023221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656010110 + 656010111.

It is an arithmetic number, because the mean of its divisors is an integer number (656010111).

Almost surely, 2^1312020221 is an apocalyptic number.

It is an amenable number.

1312020221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1312020221 is an equidigital number, since it uses as much as digits as its factorization.

1312020221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 1312020221 is about 36221.8196809603. The cubic root of 1312020221 is about 1094.7463591057.

Adding to 1312020221 its reverse (1220202131), we get a palindrome (2532222352).

The spelling of 1312020221 in words is "one billion, three hundred twelve million, twenty thousand, two hundred twenty-one".