19985659 has 4 divisors (see below), whose sum is σ = 21161304. Its totient is φ = 18810016.

The previous prime is 19985627. The next prime is 19985671. The reversal of 19985659 is 95658991.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19985659 - 2⁵ = 19985627 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19985759) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 587797 + ... + 587830.

It is an arithmetic number, because the mean of its divisors is an integer number (5290326).

Almost surely, 2^19985659 is an apocalyptic number.

19985659 is a deficient number, since it is larger than the sum of its proper divisors (1175645).

19985659 is a wasteful number, since it uses less digits than its factorization.

19985659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1175644.

The product of its digits is 874800, while the sum is 52.

The square root of 19985659 is about 4470.5322949286. The cubic root of 19985659 is about 271.3768670411.

It can be divided in two parts, 199 and 85659, that added together give a palindrome (85858).

The spelling of 19985659 in words is "nineteen million, nine hundred eighty-five thousand, six hundred fifty-nine".