201020111 has 4 divisors (see below), whose sum is σ = 201049224. Its totient is φ = 200991000.

The previous prime is 201020101. The next prime is 201020123. The reversal of 201020111 is 111020102.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 111020102 = 2 ⋅55510051.

It is a cyclic number.

It is not a de Polignac number, because 201020111 - 2⁶ = 201020047 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201020101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2336 + ... + 20186.

It is an arithmetic number, because the mean of its divisors is an integer number (50262306).

Almost surely, 2^201020111 is an apocalyptic number.

201020111 is a deficient number, since it is larger than the sum of its proper divisors (29113).

201020111 is a wasteful number, since it uses less digits than its factorization.

201020111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29112.

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 201020111 is about 14178.1561213015. The cubic root of 201020111 is about 585.7961361860.

Adding to 201020111 its reverse (111020102), we get a palindrome (312040213).

Subtracting from 201020111 its reverse (111020102), we obtain a palindrome (90000009).

The spelling of 201020111 in words is "two hundred one million, twenty thousand, one hundred eleven".