19855872 has 120 divisors (see below), whose sum is σ = 59579520. Its totient is φ = 6359040.

The previous prime is 19855859. The next prime is 19855873. The reversal of 19855872 is 27855891.

It is a happy number.

19855872 is a `hidden beast` number, since 1 + 98 + 558 + 7 + 2 = 666.

Its product of digits (201600) is a multiple of the sum of its prime divisors (175).

It is not an unprimeable number, because it can be changed into a prime (19855873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 142779 + ... + 142917.

It is an arithmetic number, because the mean of its divisors is an integer number (496496).

Almost surely, 2^19855872 is an apocalyptic number.

19855872 is a gapful number since it is divisible by the number (12) 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 19855872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29789760).

19855872 is an abundant number, since it is smaller than the sum of its proper divisors (39723648).

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

19855872 is a wasteful number, since it uses less digits than its factorization.

19855872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194 (or 175 counting only the distinct ones).

The product of its digits is 201600, while the sum is 45.

The square root of 19855872 is about 4455.9928186657. The cubic root of 19855872 is about 270.7881497694.

The spelling of 19855872 in words is "nineteen million, eight hundred fifty-five thousand, eight hundred seventy-two".