1328581809 has 12 divisors (see below), whose sum is σ = 1919438976. Its totient is φ = 885547512.

The previous prime is 1328581801. The next prime is 1328581817. The reversal of 1328581809 is 9081858231.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1328581801) and next prime (1328581817).

It is not a de Polignac number, because 1328581809 - 2³ = 1328581801 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1328581801) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 48292 + ... + 70634.

It is an arithmetic number, because the mean of its divisors is an integer number (159953248).

Almost surely, 2^1328581809 is an apocalyptic number.

It is an amenable number.

1328581809 is a deficient number, since it is larger than the sum of its proper divisors (590857167).

1328581809 is a wasteful number, since it uses less digits than its factorization.

1328581809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28956 (or 28953 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 45.

The square root of 1328581809 is about 36449.7161717345. The cubic root of 1328581809 is about 1099.3334278362. Note that the first 3 decimals are identical.

The spelling of 1328581809 in words is "one billion, three hundred twenty-eight million, five hundred eighty-one thousand, eight hundred nine".