1666207 has 4 divisors (see below), whose sum is σ = 1705000. Its totient is φ = 1627416.

The previous prime is 1666201. The next prime is 1666211. The reversal of 1666207 is 7026661.

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-1666207 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19332 + ... + 19417.

It is an arithmetic number, because the mean of its divisors is an integer number (426250).

2^1666207 is an apocalyptic number.

1666207 is a deficient number, since it is larger than the sum of its proper divisors (38793).

1666207 is an equidigital number, since it uses as much as digits as its factorization.

1666207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38792.

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 1666207 is about 1290.8164083246. The cubic root of 1666207 is about 118.5522092455.

The spelling of 1666207 in words is "one million, six hundred sixty-six thousand, two hundred seven".