201020021 has 4 divisors (see below), whose sum is σ = 204427200. Its totient is φ = 197612844.

The previous prime is 201020011. The next prime is 201020041. The reversal of 201020021 is 120020102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 201020021 - 2¹⁴ = 201003637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 201019990 and 201020008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201020011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1703501 + ... + 1703618.

It is an arithmetic number, because the mean of its divisors is an integer number (51106800).

Almost surely, 2^201020021 is an apocalyptic number.

It is an amenable number.

201020021 is a deficient number, since it is larger than the sum of its proper divisors (3407179).

201020021 is an equidigital number, since it uses as much as digits as its factorization.

201020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3407178.

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

The square root of 201020021 is about 14178.1529474047. The cubic root of 201020021 is about 585.7960487625.

Adding to 201020021 its reverse (120020102), we get a palindrome (321040123).

The spelling of 201020021 in words is "two hundred one million, twenty thousand, twenty-one".