19878 has 8 divisors (see below), whose sum is σ = 39768. Its totient is φ = 6624.

The previous prime is 19867. The next prime is 19889. The reversal of 19878 is 87891.

19878 is nontrivially palindromic in base 11.

It is an interprime number because it is at equal distance from previous prime (19867) and next prime (19889).

It is a sphenic number, since it is the product of 3 distinct primes.

19878 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1651 + ... + 1662.

It is an arithmetic number, because the mean of its divisors is an integer number (4971).

2¹⁹⁸⁷⁸ is an apocalyptic number.

19878 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19884).

19878 is a wasteful number, since it uses less digits than its factorization.

19878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3318.

The product of its digits is 4032, while the sum is 33.

The square root of 19878 is about 140.9893613008. The cubic root of 19878 is about 27.0888703998.

It can be divided in two parts, 198 and 78, that added together give a triangular number (276 = T₂₃).

The spelling of 19878 in words is "nineteen thousand, eight hundred seventy-eight".