201640 has 24 divisors (see below), whose sum is σ = 460170. Its totient is φ = 79520.

The previous prime is 201629. The next prime is 201653. The reversal of 201640 is 46102.

It can be written as a sum of positive squares in only one way, i.e., 181476 + 20164 = 426^2 + 142^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 201640.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2805 + ... + 2875.

2²⁰¹⁶⁴⁰ is an apocalyptic number.

201640 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 201640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (230085).

201640 is an abundant number, since it is smaller than the sum of its proper divisors (258530).

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

201640 is an equidigital number, since it uses as much as digits as its factorization.

201640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 201640 is about 449.0434277439. The cubic root of 201640 is about 58.6397661336.

Adding to 201640 its reverse (46102), we get a palindrome (247742).

It can be divided in two parts, 201 and 640, that added together give a square (841 = 29²).

The spelling of 201640 in words is "two hundred one thousand, six hundred forty".