201021 has 8 divisors (see below), whose sum is σ = 275424. Its totient is φ = 130320.

The previous prime is 201011. The next prime is 201031. The reversal of 201021 is 120102.

It is a happy number.

201021 is digitally balanced in base 2 and base 7, because in such bases 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 (201011) and next prime (201031).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 201021 - 2⁵ = 200989 is a prime.

201021 is strictly pandigital in base 7.

It is a Curzon number.

It is a plaindrome in base 9.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 795 + ... + 1016.

It is an arithmetic number, because the mean of its divisors is an integer number (34428).

2²⁰¹⁰²¹ is an apocalyptic number.

It is an amenable number.

201021 is a deficient number, since it is larger than the sum of its proper divisors (74403).

201021 is a wasteful number, since it uses less digits than its factorization.

201021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1851.

The product of its (nonzero) digits is 4, while the sum is 6.

The square root of 201021 is about 448.3536550537. The cubic root of 201021 is about 58.5796999735.

Adding to 201021 its reverse (120102), we get a palindrome (321123).

The spelling of 201021 in words is "two hundred one thousand, twenty-one", and thus it is an iban number.