1664866 has 16 divisors (see below), whose sum is σ = 2882880. Its totient is φ = 706320.

The previous prime is 1664863. The next prime is 1664867. The reversal of 1664866 is 6684661.

It is not an unprimeable number, because it can be changed into a prime (1664863) 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 7 ways as a sum of consecutive naturals, for example, 981 + ... + 2071.

It is an arithmetic number, because the mean of its divisors is an integer number (180180).

2^1664866 is an apocalyptic number.

1664866 is a deficient number, since it is larger than the sum of its proper divisors (1218014).

1664866 is a wasteful number, since it uses less digits than its factorization.

1664866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1209.

The product of its digits is 41472, while the sum is 37.

The square root of 1664866 is about 1290.2968650663. The cubic root of 1664866 is about 118.5203962352.

The spelling of 1664866 in words is "one million, six hundred sixty-four thousand, eight hundred sixty-six".