21012112121201 has 2 divisors, whose sum is σ = 21012112121202. Its totient is φ = 21012112121200.

The previous prime is 21012112121191. The next prime is 21012112121219. The reversal of 21012112121201 is 10212121121012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18714838384225 + 2297273736976 = 4326065^2 + 1515676^2 .

It is a cyclic number.

It is not a de Polignac number, because 21012112121201 - 2¹⁰ = 21012112120177 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21012112121201.

It is not a weakly prime, because it can be changed into another prime (21012112121251) 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, 10506056060600 + 10506056060601.

It is an arithmetic number, because the mean of its divisors is an integer number (10506056060601).

Almost surely, 2^{21012112121201} is an apocalyptic number.

It is an amenable number.

21012112121201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012112121201 is an equidigital number, since it uses as much as digits as its factorization.

21012112121201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21012112121201 its reverse (10212121121012), we get a palindrome (31224233242213).

The spelling of 21012112121201 in words is "twenty-one trillion, twelve billion, one hundred twelve million, one hundred twenty-one thousand, two hundred one".