1666945 has 16 divisors (see below), whose sum is σ = 2314368. Its totient is φ = 1128960.

The previous prime is 1666943. The next prime is 1666991. The reversal of 1666945 is 5496661.

It is not a de Polignac number, because 1666945 - 2¹ = 1666943 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1666943) 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 15 ways as a sum of consecutive naturals, for example, 3150 + ... + 3640.

It is an arithmetic number, because the mean of its divisors is an integer number (144648).

2^1666945 is an apocalyptic number.

It is an amenable number.

1666945 is a deficient number, since it is larger than the sum of its proper divisors (647423).

1666945 is an equidigital number, since it uses as much as digits as its factorization.

1666945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 600.

The product of its digits is 38880, while the sum is 37.

The square root of 1666945 is about 1291.1022422721. The cubic root of 1666945 is about 118.5697097954.

The spelling of 1666945 in words is "one million, six hundred sixty-six thousand, nine hundred forty-five".