201820200181 has 16 divisors (see below), whose sum is σ = 216864806400. Its totient is φ = 187242498288.

The previous prime is 201820200151. The next prime is 201820200203. The reversal of 201820200181 is 181002028102.

It is a cyclic number.

It is not a de Polignac number, because 201820200181 - 2⁵ = 201820200149 is a prime.

It is a super-2 number, since 2×201820200181² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201820200151) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 47451 + ... + 637096.

It is an arithmetic number, because the mean of its divisors is an integer number (13554050400).

Almost surely, 2^201820200181 is an apocalyptic number.

It is an amenable number.

201820200181 is a deficient number, since it is larger than the sum of its proper divisors (15044606219).

201820200181 is a wasteful number, since it uses less digits than its factorization.

201820200181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 684888.

The product of its (nonzero) digits is 512, while the sum is 25.

Adding to 201820200181 its reverse (181002028102), we get a palindrome (382822228283).

The spelling of 201820200181 in words is "two hundred one billion, eight hundred twenty million, two hundred thousand, one hundred eighty-one".