1666588 has 36 divisors (see below), whose sum is σ = 3705912. Its totient is φ = 648480.

The previous prime is 1666559. The next prime is 1666589. The reversal of 1666588 is 8856661.

It is a happy number.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 1666588.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666589) 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 11 ways as a sum of consecutive naturals, for example, 1770 + ... + 2542.

It is an arithmetic number, because the mean of its divisors is an integer number (102942).

2^1666588 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1666588, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1852956).

1666588 is an abundant number, since it is smaller than the sum of its proper divisors (2039324).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1666588 is a wasteful number, since it uses less digits than its factorization.

1666588 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 802 (or 793 counting only the distinct ones).

The product of its digits is 69120, while the sum is 40.

The square root of 1666588 is about 1290.9639809073. The cubic root of 1666588 is about 118.5612447274.

The spelling of 1666588 in words is "one million, six hundred sixty-six thousand, five hundred eighty-eight".