16661589 has 16 divisors (see below), whose sum is σ = 25638912. Its totient is φ = 9427248.

The previous prime is 16661563. The next prime is 16661599. The reversal of 16661589 is 98516661.

It is a happy number.

It is not a de Polignac number, because 16661589 - 2¹² = 16657493 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16661589.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16661509) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1689 + ... + 6014.

It is an arithmetic number, because the mean of its divisors is an integer number (1602432).

Almost surely, 2^16661589 is an apocalyptic number.

It is an amenable number.

16661589 is a deficient number, since it is larger than the sum of its proper divisors (8977323).

16661589 is a wasteful number, since it uses less digits than its factorization.

16661589 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7816.

The product of its digits is 77760, while the sum is 42.

The square root of 16661589 is about 4081.8609726447. The cubic root of 16661589 is about 255.4105344040.

The spelling of 16661589 in words is "sixteen million, six hundred sixty-one thousand, five hundred eighty-nine".