1323661 has 4 divisors (see below), whose sum is σ = 1351872. Its totient is φ = 1295452.

The previous prime is 1323659. The next prime is 1323689. The reversal of 1323661 is 1663231.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1663231 = 109 ⋅15259.

It is a cyclic number.

It is not a de Polignac number, because 1323661 - 2¹ = 1323659 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1323611) 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, 14035 + ... + 14128.

It is an arithmetic number, because the mean of its divisors is an integer number (337968).

2^1323661 is an apocalyptic number.

It is an amenable number.

1323661 is a deficient number, since it is larger than the sum of its proper divisors (28211).

1323661 is an equidigital number, since it uses as much as digits as its factorization.

1323661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28210.

The product of its digits is 648, while the sum is 22.

The square root of 1323661 is about 1150.5046718723. The cubic root of 1323661 is about 109.7974509557.

Adding to 1323661 its reverse (1663231), we get a palindrome (2986892).

It can be divided in two parts, 1323 and 661, that multiplied together give a triangular number (874503 = T₁₃₂₂).

The spelling of 1323661 in words is "one million, three hundred twenty-three thousand, six hundred sixty-one".