21002001221101 has 2 divisors, whose sum is σ = 21002001221102. Its totient is φ = 21002001221100.

The previous prime is 21002001221093. The next prime is 21002001221177. The reversal of 21002001221101 is 10112210020012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19437252912900 + 1564748308201 = 4408770^2 + 1250899^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002001221101 - 2³ = 21002001221093 is a prime.

It is a super-2 number, since 2×21002001221101² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21002001227101) 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, 10501000610550 + 10501000610551.

It is an arithmetic number, because the mean of its divisors is an integer number (10501000610551).

Almost surely, 2^{21002001221101} is an apocalyptic number.

It is an amenable number.

21002001221101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002001221101 is an equidigital number, since it uses as much as digits as its factorization.

21002001221101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21002001221101 its reverse (10112210020012), we get a palindrome (31114211241113).

The spelling of 21002001221101 in words is "twenty-one trillion, two billion, one million, two hundred twenty-one thousand, one hundred one".