21222220100201 has 4 divisors (see below), whose sum is σ = 21248847729732. Its totient is φ = 21195592470672.

The previous prime is 21222220100183. The next prime is 21222220100231. The reversal of 21222220100201 is 10200102222212.

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 2999131240000 + 18223088860201 = 1731800^2 + 4268851^2 .

It is a cyclic number.

It is not a de Polignac number, because 21222220100201 - 2³⁸ = 20947342193257 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21222220100201.

It is not an unprimeable number, because it can be changed into a prime (21222220100231) 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, 13313813570 + ... + 13313815163.

It is an arithmetic number, because the mean of its divisors is an integer number (5312211932433).

Almost surely, 2^{21222220100201} is an apocalyptic number.

It is an amenable number.

21222220100201 is a deficient number, since it is larger than the sum of its proper divisors (26627629531).

21222220100201 is an equidigital number, since it uses as much as digits as its factorization.

21222220100201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26627629530.

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

Adding to 21222220100201 its reverse (10200102222212), we get a palindrome (31422322322413).

The spelling of 21222220100201 in words is "twenty-one trillion, two hundred twenty-two billion, two hundred twenty million, one hundred thousand, two hundred one".