1329665 has 8 divisors (see below), whose sum is σ = 1612008. Its totient is φ = 1052800.

The previous prime is 1329661. The next prime is 1329673. The reversal of 1329665 is 5669231.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 231361 + 1098304 = 481^2 + 1048^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1329665 - 2² = 1329661 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1329661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 812 + ... + 1821.

It is an arithmetic number, because the mean of its divisors is an integer number (201501).

2^1329665 is an apocalyptic number.

It is an amenable number.

1329665 is a deficient number, since it is larger than the sum of its proper divisors (282343).

1329665 is a wasteful number, since it uses less digits than its factorization.

1329665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2739.

The product of its digits is 9720, while the sum is 32.

The square root of 1329665 is about 1153.1110094002. Note that the first 3 decimals coincide. The cubic root of 1329665 is about 109.9632108378.

It can be divided in two parts, 1329 and 665, that multiplied together give a triangular number (883785 = T₁₃₂₉).

The spelling of 1329665 in words is "one million, three hundred twenty-nine thousand, six hundred sixty-five".