21221201021201 has 4 divisors (see below), whose sum is σ = 21274121722404. Its totient is φ = 21168280320000.

The previous prime is 21221201021183. The next prime is 21221201021203. The reversal of 21221201021201 is 10212010212212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10223852770576 + 10997348250625 = 3197476^2 + 3316225^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221201021201 - 2²⁶ = 21221133912337 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 21221201021201.

It is not an unprimeable number, because it can be changed into a prime (21221201021203) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26460350000 + ... + 26460350801.

It is an arithmetic number, because the mean of its divisors is an integer number (5318530430601).

Almost surely, 2^{21221201021201} is an apocalyptic number.

It is an amenable number.

21221201021201 is a deficient number, since it is larger than the sum of its proper divisors (52920701203).

21221201021201 is an equidigital number, since it uses as much as digits as its factorization.

21221201021201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52920701202.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21221201021201 its reverse (10212010212212), we get a palindrome (31433211233413).

The spelling of 21221201021201 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred one million, twenty-one thousand, two hundred one".