21222111112001 has 4 divisors (see below), whose sum is σ = 21222120603732. Its totient is φ = 21222101620272.

The previous prime is 21222111111979. The next prime is 21222111112061. The reversal of 21222111112001 is 10021111122212.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 13016040450625 + 8206070661376 = 3607775^2 + 2864624^2 .

It is a cyclic number.

It is not a de Polignac number, because 21222111112001 - 2¹⁴ = 21222111095617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21222111112061) 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, 661931 + ... + 6548463.

It is an arithmetic number, because the mean of its divisors is an integer number (5305530150933).

Almost surely, 2^{21222111112001} is an apocalyptic number.

It is an amenable number.

21222111112001 is a deficient number, since it is larger than the sum of its proper divisors (9491731).

21222111112001 is an equidigital number, since it uses as much as digits as its factorization.

21222111112001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9491730.

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

Adding to 21222111112001 its reverse (10021111122212), we get a palindrome (31243222234213).

The spelling of 21222111112001 in words is "twenty-one trillion, two hundred twenty-two billion, one hundred eleven million, one hundred twelve thousand, one".