1309739243 has 4 divisors (see below), whose sum is σ = 1351988928. Its totient is φ = 1267489560.

The previous prime is 1309739239. The next prime is 1309739251. The reversal of 1309739243 is 3429379031.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1309739243 - 2² = 1309739239 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1309739243.

It is not an unprimeable number, because it can be changed into a prime (1309739203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21124796 + ... + 21124857.

It is an arithmetic number, because the mean of its divisors is an integer number (337997232).

Almost surely, 2^1309739243 is an apocalyptic number.

1309739243 is a deficient number, since it is larger than the sum of its proper divisors (42249685).

1309739243 is an equidigital number, since it uses as much as digits as its factorization.

1309739243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42249684.

The product of its (nonzero) digits is 122472, while the sum is 41.

The square root of 1309739243 is about 36190.3197416105. The cubic root of 1309739243 is about 1094.1115770079. Note that the first 3 decimals are identical.

The spelling of 1309739243 in words is "one billion, three hundred nine million, seven hundred thirty-nine thousand, two hundred forty-three".