19985998 has 16 divisors (see below), whose sum is σ = 30818880. Its totient is φ = 9715936.

The previous prime is 19985969. The next prime is 19986019. The reversal of 19985998 is 89958991.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 15648 + ... + 16876.

It is an arithmetic number, because the mean of its divisors is an integer number (1926180).

Almost surely, 2^19985998 is an apocalyptic number.

19985998 is a deficient number, since it is larger than the sum of its proper divisors (10832882).

19985998 is a wasteful number, since it uses less digits than its factorization.

19985998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1451.

The product of its digits is 2099520, while the sum is 58.

The square root of 19985998 is about 4470.5702097160. The cubic root of 19985998 is about 271.3784014119.

The spelling of 19985998 in words is "nineteen million, nine hundred eighty-five thousand, nine hundred ninety-eight".