1312718821 has 2 divisors, whose sum is σ = 1312718822. Its totient is φ = 1312718820.

The previous prime is 1312718791. The next prime is 1312718831. The reversal of 1312718821 is 1288172131.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1050732225 + 261986596 = 32415^2 + 16186^2 .

It is a cyclic number.

It is not a de Polignac number, because 1312718821 - 2¹³ = 1312710629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1312718831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656359410 + 656359411.

It is an arithmetic number, because the mean of its divisors is an integer number (656359411).

Almost surely, 2^1312718821 is an apocalyptic number.

It is an amenable number.

1312718821 is a deficient number, since it is larger than the sum of its proper divisors (1).

1312718821 is an equidigital number, since it uses as much as digits as its factorization.

1312718821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5376, while the sum is 34.

The square root of 1312718821 is about 36231.4617563244. The cubic root of 1312718821 is about 1094.9406279881.

The spelling of 1312718821 in words is "one billion, three hundred twelve million, seven hundred eighteen thousand, eight hundred twenty-one".