19985400 has 96 divisors (see below), whose sum is σ = 68857200. Its totient is φ = 5328000.

The previous prime is 19985351. The next prime is 19985401. The reversal of 19985400 is 458991.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19985401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3550 + ... + 7250.

Almost surely, 2^19985400 is an apocalyptic number.

19985400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19985400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34428600).

19985400 is an abundant number, since it is smaller than the sum of its proper divisors (48871800).

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

19985400 is a wasteful number, since it uses less digits than its factorization.

19985400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3726 (or 3711 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 19985400 is about 4470.5033273671. The cubic root of 19985400 is about 271.3756947519.

The spelling of 19985400 in words is "nineteen million, nine hundred eighty-five thousand, four hundred".