1666161 has 24 divisors (see below), whose sum is σ = 2808000. Its totient is φ = 932256.

The previous prime is 1666151. The next prime is 1666177. The reversal of 1666161 is 1616661.

It is not a de Polignac number, because 1666161 - 2⁹ = 1665649 is a prime.

1666161 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1666111) 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 23 ways as a sum of consecutive naturals, for example, 3090 + ... + 3588.

It is an arithmetic number, because the mean of its divisors is an integer number (117000).

2^1666161 is an apocalyptic number.

It is an amenable number.

1666161 is a deficient number, since it is larger than the sum of its proper divisors (1141839).

1666161 is a wasteful number, since it uses less digits than its factorization.

1666161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 565 (or 562 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 1666161 is about 1290.7985900209. The cubic root of 1666161 is about 118.5511182543.

The spelling of 1666161 in words is "one million, six hundred sixty-six thousand, one hundred sixty-one".