21000100011001 has 2 divisors, whose sum is σ = 21000100011002. Its totient is φ = 21000100011000.

The previous prime is 21000100010983. The next prime is 21000100011017. The reversal of 21000100011001 is 10011000100012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20433121130601 + 566978880400 = 4520301^2 + 752980^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000100011001 - 2¹⁹ = 21000099486713 is a prime.

It is not a weakly prime, because it can be changed into another prime (21000100011071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500050005500 + 10500050005501.

It is an arithmetic number, because the mean of its divisors is an integer number (10500050005501).

Almost surely, 2^{21000100011001} is an apocalyptic number.

It is an amenable number.

21000100011001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000100011001 is an equidigital number, since it uses as much as digits as its factorization.

21000100011001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2, while the sum is 7.

Adding to 21000100011001 its reverse (10011000100012), we get a palindrome (31011100111013).

The spelling of 21000100011001 in words is "twenty-one trillion, one hundred million, eleven thousand, one".