2021121020021 has 4 divisors (see below), whose sum is σ = 2075745912492. Its totient is φ = 1966496127552.

The previous prime is 2021121019999. The next prime is 2021121020047. The reversal of 2021121020021 is 1200201211202.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1220384184100 + 800736835921 = 1104710^2 + 894839^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021121020021 - 2²⁶ = 2021053911157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2021121019978 and 2021121020005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021121020081) 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, 27312446180 + ... + 27312446253.

It is an arithmetic number, because the mean of its divisors is an integer number (518936478123).

Almost surely, 2^{2021121020021} is an apocalyptic number.

It is an amenable number.

2021121020021 is a deficient number, since it is larger than the sum of its proper divisors (54624892471).

2021121020021 is an equidigital number, since it uses as much as digits as its factorization.

2021121020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54624892470.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 2021121020021 its reverse (1200201211202), we get a palindrome (3221322231223).

The spelling of 2021121020021 in words is "two trillion, twenty-one billion, one hundred twenty-one million, twenty thousand, twenty-one".