2021320121 has 4 divisors (see below), whose sum is σ = 2021430144. Its totient is φ = 2021210100.

The previous prime is 2021320099. The next prime is 2021320123. The reversal of 2021320121 is 1210231202.

It is a happy number.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1210231202 = 2 ⋅605115601.

It is a cyclic number.

It is not a de Polignac number, because 2021320121 - 2²⁶ = 1954211257 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2021320096 and 2021320105.

It is not an unprimeable number, because it can be changed into a prime (2021320123) 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, 20045 + ... + 66666.

It is an arithmetic number, because the mean of its divisors is an integer number (505357536).

Almost surely, 2^2021320121 is an apocalyptic number.

It is an amenable number.

2021320121 is a deficient number, since it is larger than the sum of its proper divisors (110023).

2021320121 is an equidigital number, since it uses as much as digits as its factorization.

2021320121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110022.

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

The square root of 2021320121 is about 44959.0938631997. The cubic root of 2021320121 is about 1264.3821801474.

Adding to 2021320121 its reverse (1210231202), we get a palindrome (3231551323).

The spelling of 2021320121 in words is "two billion, twenty-one million, three hundred twenty thousand, one hundred twenty-one".