189840 has 80 divisors (see below), whose sum is σ = 678528. Its totient is φ = 43008.

The previous prime is 189823. The next prime is 189851. The reversal of 189840 is 48981.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 189798 and 189807.

It is a Saint-Exupery number, since it is equal to the product of the sides of a Pythagorean triangle: 113 × 15 × 112.

It is an unprimeable number.

189840 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1624 + ... + 1736.

2¹⁸⁹⁸⁴⁰ is an apocalyptic number.

189840 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 189840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (339264).

189840 is an abundant number, since it is smaller than the sum of its proper divisors (488688).

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

189840 is a wasteful number, since it uses less digits than its factorization.

189840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136 (or 130 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 30.

The square root of 189840 is about 435.7063231123. The cubic root of 189840 is about 57.4728290026.

189840 divided by its sum of digits (30) gives a triangular number (6328 = T₁₁₂).

The spelling of 189840 in words is "one hundred eighty-nine thousand, eight hundred forty".