1309447643 has 32 divisors (see below), whose sum is σ = 1638336000. Its totient is φ = 1021144320.

The previous prime is 1309447621. The next prime is 1309447663. The reversal of 1309447643 is 3467449031.

It is not a de Polignac number, because 1309447643 - 2³⁰ = 235705819 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1309447643.

It is not an unprimeable number, because it can be changed into a prime (1309447603) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 813023 + ... + 814631.

It is an arithmetic number, because the mean of its divisors is an integer number (51198000).

Almost surely, 2^1309447643 is an apocalyptic number.

1309447643 is a deficient number, since it is larger than the sum of its proper divisors (328888357).

1309447643 is a wasteful number, since it uses less digits than its factorization.

1309447643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1875.

The product of its (nonzero) digits is 217728, while the sum is 41.

The square root of 1309447643 is about 36186.2908157219. The cubic root of 1309447643 is about 1094.0303734102.

The spelling of 1309447643 in words is "one billion, three hundred nine million, four hundred forty-seven thousand, six hundred forty-three".