21002122022201 has 4 divisors (see below), whose sum is σ = 21007371244404. Its totient is φ = 20996872800000.

The previous prime is 21002122022183. The next prime is 21002122022207. The reversal of 21002122022201 is 10222022120012.

It is a happy number.

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 3304105998400 + 17698016023801 = 1817720^2 + 4206901^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002122022201 - 2¹⁴ = 21002122005817 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 21002122022201.

It is not an unprimeable number, because it can be changed into a prime (21002122022207) 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, 2624605100 + ... + 2624613101.

It is an arithmetic number, because the mean of its divisors is an integer number (5251842811101).

Almost surely, 2^{21002122022201} is an apocalyptic number.

It is an amenable number.

21002122022201 is a deficient number, since it is larger than the sum of its proper divisors (5249222203).

21002122022201 is an equidigital number, since it uses as much as digits as its factorization.

21002122022201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5249222202.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21002122022201 its reverse (10222022120012), we get a palindrome (31224144142213).

The spelling of 21002122022201 in words is "twenty-one trillion, two billion, one hundred twenty-two million, twenty-two thousand, two hundred one".