21222112222001 has 4 divisors (see below), whose sum is σ = 21259409432100. Its totient is φ = 21184815011904.

The previous prime is 21222112221991. The next prime is 21222112222009. The reversal of 21222112222001 is 10022221122212.

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 2966830557601 + 18255281664400 = 1722449^2 + 4272620^2 .

It is a cyclic number.

It is not a de Polignac number, because 21222112222001 - 2¹⁰ = 21222112220977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21222112222009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18648604196 + ... + 18648605333.

It is an arithmetic number, because the mean of its divisors is an integer number (5314852358025).

Almost surely, 2^{21222112222001} is an apocalyptic number.

It is an amenable number.

21222112222001 is a deficient number, since it is larger than the sum of its proper divisors (37297210099).

21222112222001 is an equidigital number, since it uses as much as digits as its factorization.

21222112222001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37297210098.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21222112222001 its reverse (10022221122212), we get a palindrome (31244333344213).

The spelling of 21222112222001 in words is "twenty-one trillion, two hundred twenty-two billion, one hundred twelve million, two hundred twenty-two thousand, one".