21021001102001 has 2 divisors, whose sum is σ = 21021001102002. Its totient is φ = 21021001102000.

The previous prime is 21021001101967. The next prime is 21021001102009. The reversal of 21021001102001 is 10020110012012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13534341999025 + 7486659102976 = 3678905^2 + 2736176^2 .

It is a cyclic number.

It is not a de Polignac number, because 21021001102001 - 2⁶ = 21021001101937 is a prime.

It is not a weakly prime, because it can be changed into another prime (21021001102009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510500551000 + 10510500551001.

It is an arithmetic number, because the mean of its divisors is an integer number (10510500551001).

Almost surely, 2^{21021001102001} is an apocalyptic number.

It is an amenable number.

21021001102001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021001102001 is an equidigital number, since it uses as much as digits as its factorization.

21021001102001 is an odious number, because the sum of its binary digits is odd.

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

Adding to 21021001102001 its reverse (10020110012012), we get a palindrome (31041111114013).

The spelling of 21021001102001 in words is "twenty-one trillion, twenty-one billion, one million, one hundred two thousand, one".