2021002112821 has 2 divisors, whose sum is σ = 2021002112822. Its totient is φ = 2021002112820.

The previous prime is 2021002112761. The next prime is 2021002112839. The reversal of 2021002112821 is 1282112001202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2007704794225 + 13297318596 = 1416935^2 + 115314^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021002112821 - 2²³ = 2020993724213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2021002112792 and 2021002112801.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021002112851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010501056410 + 1010501056411.

It is an arithmetic number, because the mean of its divisors is an integer number (1010501056411).

Almost surely, 2^{2021002112821} is an apocalyptic number.

It is an amenable number.

2021002112821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021002112821 is an equidigital number, since it uses as much as digits as its factorization.

2021002112821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256, while the sum is 22.

The spelling of 2021002112821 in words is "two trillion, twenty-one billion, two million, one hundred twelve thousand, eight hundred twenty-one".