1329661 has 2 divisors, whose sum is σ = 1329662. Its totient is φ = 1329660.

The previous prime is 1329637. The next prime is 1329673. The reversal of 1329661 is 1669231.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1243225 + 86436 = 1115^2 + 294^2 .

It is an emirp because it is prime and its reverse (1669231) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1329661 - 2⁷ = 1329533 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1329631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 664830 + 664831.

It is an arithmetic number, because the mean of its divisors is an integer number (664831).

2^1329661 is an apocalyptic number.

It is an amenable number.

1329661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1329661 is an equidigital number, since it uses as much as digits as its factorization.

1329661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1944, while the sum is 28.

The square root of 1329661 is about 1153.1092749605. The cubic root of 1329661 is about 109.9631005712.

The spelling of 1329661 in words is "one million, three hundred twenty-nine thousand, six hundred sixty-one".