21012211121201 has 8 divisors (see below), whose sum is σ = 21156571674600. Its totient is φ = 20867895088128.

The previous prime is 21012211121189. The next prime is 21012211121333. The reversal of 21012211121201 is 10212111221012.

It can be written as a sum of positive squares in 4 ways, for example, as 530712250000 + 20481498871201 = 728500^2 + 4525649^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21012211121201 - 2¹⁰ = 21012211120177 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21012211121201.

It is not an unprimeable number, because it can be changed into a prime (21012211121801) 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 in 7 ways as a sum of consecutive naturals, for example, 10182626 + ... + 12071051.

It is an arithmetic number, because the mean of its divisors is an integer number (2644571459325).

Almost surely, 2^{21012211121201} is an apocalyptic number.

It is an amenable number.

21012211121201 is a deficient number, since it is larger than the sum of its proper divisors (144360553399).

21012211121201 is a wasteful number, since it uses less digits than its factorization.

21012211121201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22260163.

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

Adding to 21012211121201 its reverse (10212111221012), we get a palindrome (31224322342213).

The spelling of 21012211121201 in words is "twenty-one trillion, twelve billion, two hundred eleven million, one hundred twenty-one thousand, two hundred one".