19928172 has 48 divisors (see below), whose sum is σ = 51028992. Its totient is φ = 6002880.

The previous prime is 19928171. The next prime is 19928177. The reversal of 19928172 is 27182991.

It is a super-3 number, since 3×19928172³ (a number of 23 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 19928172.

It is not an unprimeable number, because it can be changed into a prime (19928171) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29098 + ... + 29774.

It is an arithmetic number, because the mean of its divisors is an integer number (1063104).

Almost surely, 2^19928172 is an apocalyptic number.

19928172 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 19928172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25514496).

19928172 is an abundant number, since it is smaller than the sum of its proper divisors (31100820).

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

19928172 is a wasteful number, since it uses less digits than its factorization.

19928172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 918 (or 916 counting only the distinct ones).

The product of its digits is 18144, while the sum is 39.

The square root of 19928172 is about 4464.0981172013. The cubic root of 19928172 is about 271.1164198897.

It can be divided in two parts, 19928 and 172, that added together give a triangular number (20100 = T₂₀₀).

The spelling of 19928172 in words is "nineteen million, nine hundred twenty-eight thousand, one hundred seventy-two".