21201002121001 has 2 divisors, whose sum is σ = 21201002121002. Its totient is φ = 21201002121000.

The previous prime is 21201002120971. The next prime is 21201002121007. The reversal of 21201002121001 is 10012120010212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20107511539600 + 1093490581401 = 4484140^2 + 1045701^2 .

It is a cyclic number.

It is not a de Polignac number, because 21201002121001 - 2¹⁷ = 21201001989929 is a prime.

It is not a weakly prime, because it can be changed into another prime (21201002121007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600501060500 + 10600501060501.

It is an arithmetic number, because the mean of its divisors is an integer number (10600501060501).

Almost surely, 2^{21201002121001} is an apocalyptic number.

It is an amenable number.

21201002121001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201002121001 is an equidigital number, since it uses as much as digits as its factorization.

21201002121001 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 21201002121001 its reverse (10012120010212), we get a palindrome (31213122131213).

The spelling of 21201002121001 in words is "twenty-one trillion, two hundred one billion, two million, one hundred twenty-one thousand, one".