1309439887 has 16 divisors (see below), whose sum is σ = 1593446400. Its totient is φ = 1073571576.

The previous prime is 1309439869. The next prime is 1309439899. The reversal of 1309439887 is 7889349031.

It is a de Polignac number, because none of the positive numbers 2^k-1309439887 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1309439867) 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 in 15 ways as a sum of consecutive naturals, for example, 75103 + ... + 90880.

It is an arithmetic number, because the mean of its divisors is an integer number (99590400).

Almost surely, 2^1309439887 is an apocalyptic number.

1309439887 is a deficient number, since it is larger than the sum of its proper divisors (284006513).

1309439887 is an equidigital number, since it uses as much as digits as its factorization.

1309439887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166027 (or 166013 counting only the distinct ones).

The product of its (nonzero) digits is 1306368, while the sum is 52.

The square root of 1309439887 is about 36186.1836479063. The cubic root of 1309439887 is about 1094.0282133858.

The spelling of 1309439887 in words is "one billion, three hundred nine million, four hundred thirty-nine thousand, eight hundred eighty-seven".