1661323 has 4 divisors (see below), whose sum is σ = 1718640. Its totient is φ = 1604008.

The previous prime is 1661311. The next prime is 1661327. The reversal of 1661323 is 3231661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1661323 is a prime.

It is a super-2 number, since 2×1661323² = 5519988220658, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1661294 and 1661303.

It is not an unprimeable number, because it can be changed into a prime (1661327) 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, 28615 + ... + 28672.

It is an arithmetic number, because the mean of its divisors is an integer number (429660).

2^1661323 is an apocalyptic number.

1661323 is a deficient number, since it is larger than the sum of its proper divisors (57317).

1661323 is an equidigital number, since it uses as much as digits as its factorization.

1661323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57316.

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

The square root of 1661323 is about 1288.9231939879. The cubic root of 1661323 is about 118.4362621383.

Adding to 1661323 its reverse (3231661), we get a palindrome (4892984).

The spelling of 1661323 in words is "one million, six hundred sixty-one thousand, three hundred twenty-three".