1020002012021 has 2 divisors, whose sum is σ = 1020002012022. Its totient is φ = 1020002012020.

The previous prime is 1020002011997. The next prime is 1020002012023. The reversal of 1020002012021 is 1202102000201.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1014222211396 + 5779800625 = 1007086^2 + 76025^2 .

It is an emirp because it is prime and its reverse (1202102000201) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1020002012021 - 2²² = 1019997817717 is a prime.

It is a Sophie Germain prime.

Together with 1020002012023, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1020002011993 and 1020002012011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1020002012023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510001006010 + 510001006011.

It is an arithmetic number, because the mean of its divisors is an integer number (510001006011).

Almost surely, 2^{1020002012021} is an apocalyptic number.

It is an amenable number.

1020002012021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1020002012021 is an equidigital number, since it uses as much as digits as its factorization.

1020002012021 is an evil number, because the sum of its binary digits is even.

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

Adding to 1020002012021 its reverse (1202102000201), we get a palindrome (2222104012222).

The spelling of 1020002012021 in words is "one trillion, twenty billion, two million, twelve thousand, twenty-one".