2021121001001 has 2 divisors, whose sum is σ = 2021121001002. Its totient is φ = 2021121001000.

The previous prime is 2021121000991. The next prime is 2021121001019. The reversal of 2021121001001 is 1001001211202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1420959361600 + 600161639401 = 1192040^2 + 774701^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021121001001 - 2¹⁰ = 2021120999977 is a prime.

It is not a weakly prime, because it can be changed into another prime (2021121001091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010560500500 + 1010560500501.

It is an arithmetic number, because the mean of its divisors is an integer number (1010560500501).

Almost surely, 2^{2021121001001} is an apocalyptic number.

It is an amenable number.

2021121001001 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021121001001 is an equidigital number, since it uses as much as digits as its factorization.

2021121001001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 2021121001001 its reverse (1001001211202), we get a palindrome (3022122212203).

The spelling of 2021121001001 in words is "two trillion, twenty-one billion, one hundred twenty-one million, one thousand, one".