1309861873 has 2 divisors, whose sum is σ = 1309861874. Its totient is φ = 1309861872.

The previous prime is 1309861867. The next prime is 1309861877. The reversal of 1309861873 is 3781689031.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1186940304 + 122921569 = 34452^2 + 11087^2 .

It is an emirp because it is prime and its reverse (3781689031) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1309861873 - 2⁵ = 1309861841 is a prime.

It is not a weakly prime, because it can be changed into another prime (1309861877) 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, 654930936 + 654930937.

It is an arithmetic number, because the mean of its divisors is an integer number (654930937).

Almost surely, 2^1309861873 is an apocalyptic number.

It is an amenable number.

1309861873 is a deficient number, since it is larger than the sum of its proper divisors (1).

1309861873 is an equidigital number, since it uses as much as digits as its factorization.

1309861873 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 217728, while the sum is 46.

The square root of 1309861873 is about 36192.0139395420. The cubic root of 1309861873 is about 1094.1457229181.

The spelling of 1309861873 in words is "one billion, three hundred nine million, eight hundred sixty-one thousand, eight hundred seventy-three".