21125636531201 has 2 divisors, whose sum is σ = 21125636531202. Its totient is φ = 21125636531200.

The previous prime is 21125636531189. The next prime is 21125636531269. The reversal of 21125636531201 is 10213563652112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17508793291201 + 3616843240000 = 4184351^2 + 1901800^2 .

It is a cyclic number.

It is not a de Polignac number, because 21125636531201 - 2¹⁰ = 21125636530177 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21125636531291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10562818265600 + 10562818265601.

It is an arithmetic number, because the mean of its divisors is an integer number (10562818265601).

Almost surely, 2^{21125636531201} is an apocalyptic number.

It is an amenable number.

21125636531201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21125636531201 is an equidigital number, since it uses as much as digits as its factorization.

21125636531201 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64800, while the sum is 38.

The spelling of 21125636531201 in words is "twenty-one trillion, one hundred twenty-five billion, six hundred thirty-six million, five hundred thirty-one thousand, two hundred one".