2021020121 has 8 divisors (see below), whose sum is σ = 2109894600. Its totient is φ = 1933424640.

The previous prime is 2021020091. The next prime is 2021020147. The reversal of 2021020121 is 1210201202.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 188238400 + 1832781721 = 13720^2 + 42811^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 2021020121 - 2¹⁰ = 2021019097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2021020171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 316520 + ... + 322841.

It is an arithmetic number, because the mean of its divisors is an integer number (263736825).

Almost surely, 2^2021020121 is an apocalyptic number.

It is an amenable number.

2021020121 is a deficient number, since it is larger than the sum of its proper divisors (88874479).

2021020121 is a wasteful number, since it uses less digits than its factorization.

2021020121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 639499.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 2021020121 is about 44955.7573732220. The cubic root of 2021020121 is about 1264.3196247548.

Adding to 2021020121 its reverse (1210201202), we get a palindrome (3231221323).

The spelling of 2021020121 in words is "two billion, twenty-one million, twenty thousand, one hundred twenty-one".