2021230121 has 4 divisors (see below), whose sum is σ = 2023900932. Its totient is φ = 2018559312.

The previous prime is 2021230109. The next prime is 2021230129. The reversal of 2021230121 is 1210321202.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1210321202 = 2 ⋅605160601.

It can be written as a sum of positive squares in 2 ways, for example, as 1758628096 + 262602025 = 41936^2 + 16205^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021230121 - 2¹⁴ = 2021213737 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2021230096 and 2021230105.

It is not an unprimeable number, because it can be changed into a prime (2021230129) 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, 1334270 + ... + 1335783.

It is an arithmetic number, because the mean of its divisors is an integer number (505975233).

Almost surely, 2^2021230121 is an apocalyptic number.

It is an amenable number.

2021230121 is a deficient number, since it is larger than the sum of its proper divisors (2670811).

2021230121 is an equidigital number, since it uses as much as digits as its factorization.

2021230121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2670810.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 2021230121 is about 44958.0929422056. The cubic root of 2021230121 is about 1264.3634141796.

Adding to 2021230121 its reverse (1210321202), we get a palindrome (3231551323).

The spelling of 2021230121 in words is "two billion, twenty-one million, two hundred thirty thousand, one hundred twenty-one".