201840 has 60 divisors (see below), whose sum is σ = 648024. Its totient is φ = 51968.

The previous prime is 201833. The next prime is 201847. The reversal of 201840 is 48102.

201840 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (201833) and next prime (201847).

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201847) 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 11 ways as a sum of consecutive naturals, for example, 6946 + ... + 6974.

2²⁰¹⁸⁴⁰ is an apocalyptic number.

201840 is a gapful number since it is divisible by the number (20) 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 201840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (324012).

201840 is an abundant number, since it is smaller than the sum of its proper divisors (446184).

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

201840 is a wasteful number, since it uses less digits than its factorization.

201840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74 (or 39 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

The square root of 201840 is about 449.2660681601. The cubic root of 201840 is about 58.6591473375.

Multiplying 201840 by its sum of digits (15), we get a square (3027600 = 1740²).

201840 divided by its sum of digits (15) gives a square (13456 = 116²).

Adding to 201840 its reverse (48102), we get a palindrome (249942).

The spelling of 201840 in words is "two hundred one thousand, eight hundred forty".