19812 has 24 divisors (see below), whose sum is σ = 50176. Its totient is φ = 6048.

The previous prime is 19801. The next prime is 19813. The reversal of 19812 is 21891.

It is a Smith number, since the sum of its digits (21) 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 (19813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 93 + ... + 219.

2¹⁹⁸¹² is an apocalyptic number.

19812 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 19812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25088).

19812 is an abundant number, since it is smaller than the sum of its proper divisors (30364).

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

19812 is a wasteful number, since it uses less digits than its factorization.

19812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147 (or 145 counting only the distinct ones).

The product of its digits is 144, while the sum is 21.

The square root of 19812 is about 140.7551064793. The cubic root of 19812 is about 27.0588565180.

Subtracting from 19812 its sum of digits (21), we obtain a palindrome (19791).

It can be divided in two parts, 198 and 12, that added together give a triangular number (210 = T₂₀).

The spelling of 19812 in words is "nineteen thousand, eight hundred twelve".