1329809 has 4 divisors (see below), whose sum is σ = 1432116. Its totient is φ = 1227504.

The previous prime is 1329799. The next prime is 1329847. The reversal of 1329809 is 9089231.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9089231 = 31 ⋅293201.

It can be written as a sum of positive squares in 2 ways, for example, as 180625 + 1149184 = 425^2 + 1072^2 .

It is a cyclic number.

It is not a de Polignac number, because 1329809 - 2²⁰ = 281233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1329899) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51134 + ... + 51159.

It is an arithmetic number, because the mean of its divisors is an integer number (358029).

2^1329809 is an apocalyptic number.

It is an amenable number.

1329809 is a deficient number, since it is larger than the sum of its proper divisors (102307).

1329809 is a wasteful number, since it uses less digits than its factorization.

1329809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102306.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 1329809 is about 1153.1734474917. The cubic root of 1329809 is about 109.9671802915.

The spelling of 1329809 in words is "one million, three hundred twenty-nine thousand, eight hundred nine".