1661443 has 12 divisors (see below), whose sum is σ = 1982232. Its totient is φ = 1387680.

The previous prime is 1661441. The next prime is 1661447. The reversal of 1661443 is 3441661.

It is not a de Polignac number, because 1661443 - 2¹ = 1661441 is a prime.

It is a zygodrome in base 6.

It is not an unprimeable number, because it can be changed into a prime (1661441) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1596 + ... + 2422.

It is an arithmetic number, because the mean of its divisors is an integer number (165186).

2^1661443 is an apocalyptic number.

1661443 is a deficient number, since it is larger than the sum of its proper divisors (320789).

1661443 is an equidigital number, since it uses as much as digits as its factorization.

1661443 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 882 (or 875 counting only the distinct ones).

The product of its digits is 1728, while the sum is 25.

The square root of 1661443 is about 1288.9697436325. The cubic root of 1661443 is about 118.4391136828.

The spelling of 1661443 in words is "one million, six hundred sixty-one thousand, four hundred forty-three".