19985900 has 36 divisors (see below), whose sum is σ = 47314680. Its totient is φ = 7267200.

The previous prime is 19985869. The next prime is 19985909. The reversal of 19985900 is 958991.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (19985909) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7985 + ... + 10184.

Almost surely, 2^19985900 is an apocalyptic number.

19985900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19985900 is an abundant number, since it is smaller than the sum of its proper divisors (27328780).

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

19985900 is a wasteful number, since it uses less digits than its factorization.

19985900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18194 (or 18187 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 41.

The square root of 19985900 is about 4470.5592491320. The cubic root of 19985900 is about 271.3779578493.

The spelling of 19985900 in words is "nineteen million, nine hundred eighty-five thousand, nine hundred".