19816000 has 56 divisors (see below), whose sum is σ = 49094136. Its totient is φ = 7923200.

The previous prime is 19815973. The next prime is 19816007. The reversal of 19816000 is 61891.

It can be written as a sum of positive squares in 4 ways, for example, as 876096 + 18939904 = 936^2 + 4352^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (19816007) 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 7 ways as a sum of consecutive naturals, for example, 6762 + ... + 9238.

It is an arithmetic number, because the mean of its divisors is an integer number (876681).

Almost surely, 2^19816000 is an apocalyptic number.

19816000 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 19816000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24547068).

19816000 is an abundant number, since it is smaller than the sum of its proper divisors (29278136).

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

19816000 is an equidigital number, since it uses as much as digits as its factorization.

19816000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2504 (or 2484 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 19816000 is about 4451.5165954987. The cubic root of 19816000 is about 270.6067743701.

Adding to 19816000 its reverse (61891), we get a palindrome (19877891).

The spelling of 19816000 in words is "nineteen million, eight hundred sixteen thousand".