1330661 has 4 divisors (see below), whose sum is σ = 1332972. Its totient is φ = 1328352.

The previous prime is 1330649. The next prime is 1330691. The reversal of 1330661 is 1660331.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1660331 = 53 ⋅31327.

It can be written as a sum of positive squares in 2 ways, for example, as 185761 + 1144900 = 431^2 + 1070^2 .

It is a cyclic number.

It is not a de Polignac number, because 1330661 - 2¹⁰ = 1329637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1330601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 491 + ... + 1703.

It is an arithmetic number, because the mean of its divisors is an integer number (333243).

2^1330661 is an apocalyptic number.

It is an amenable number.

1330661 is a deficient number, since it is larger than the sum of its proper divisors (2311).

1330661 is a wasteful number, since it uses less digits than its factorization.

1330661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2310.

The product of its (nonzero) digits is 324, while the sum is 20.

The square root of 1330661 is about 1153.5428037138. The cubic root of 1330661 is about 109.9906603641.

Adding to 1330661 its reverse (1660331), we get a palindrome (2990992).

It can be divided in two parts, 1330 and 661, that added together give a palindrome (1991).

The spelling of 1330661 in words is "one million, three hundred thirty thousand, six hundred sixty-one".