19810 has 16 divisors (see below), whose sum is σ = 40896. Its totient is φ = 6768.

The previous prime is 19801. The next prime is 19813. The reversal of 19810 is 1891.

It is a super-2 number, since 2×19810² = 784872200, which contains 22 as substring.

It is an Ulam number.

It is a nialpdrome in base 14.

It is a congruent number.

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, 72 + ... + 211.

It is an arithmetic number, because the mean of its divisors is an integer number (2556).

2¹⁹⁸¹⁰ is an apocalyptic number.

19810 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

19810 is an abundant number, since it is smaller than the sum of its proper divisors (21086).

It is a weird number, because it is abundant, but not a pseudoperfect number.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20448).

19810 is a wasteful number, since it uses less digits than its factorization.

19810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297.

The product of its (nonzero) digits is 72, while the sum is 19.

The square root of 19810 is about 140.7480017620. The cubic root of 19810 is about 27.0579459666.

Subtracting from 19810 its sum of digits (19), we obtain a palindrome (19791).

The spelling of 19810 in words is "nineteen thousand, eight hundred ten".