1309781287 has 2 divisors, whose sum is σ = 1309781288. Its totient is φ = 1309781286.

The previous prime is 1309781261. The next prime is 1309781309. The reversal of 1309781287 is 7821879031.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1309781287 - 2¹⁵ = 1309748519 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1309781237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 654890643 + 654890644.

It is an arithmetic number, because the mean of its divisors is an integer number (654890644).

Almost surely, 2^1309781287 is an apocalyptic number.

1309781287 is a deficient number, since it is larger than the sum of its proper divisors (1).

1309781287 is an equidigital number, since it uses as much as digits as its factorization.

1309781287 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 169344, while the sum is 46.

The square root of 1309781287 is about 36190.9006105126. The cubic root of 1309781287 is about 1094.1232842581.

The spelling of 1309781287 in words is "one billion, three hundred nine million, seven hundred eighty-one thousand, two hundred eighty-seven".