21222111212001 has 48 divisors (see below), whose sum is σ = 36576475099200. Its totient is φ = 12125852274816.

The previous prime is 21222111211991. The next prime is 21222111212009. The reversal of 21222111212001 is 10021211122212.

21222111212001 is a `hidden beast` number, since 212 + 221 + 11 + 21 + 200 + 1 = 666.

It is not a de Polignac number, because 21222111212001 - 2¹⁸ = 21222110949857 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21222111212009) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 14438185 + ... + 15839993.

It is an arithmetic number, because the mean of its divisors is an integer number (762009897900).

Almost surely, 2^{21222111212001} is an apocalyptic number.

21222111212001 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21222111212001 is a deficient number, since it is larger than the sum of its proper divisors (15354363887199).

21222111212001 is a wasteful number, since it uses less digits than its factorization.

21222111212001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1413275 (or 1413262 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21222111212001 its reverse (10021211122212), we get a palindrome (31243322334213).

The spelling of 21222111212001 in words is "twenty-one trillion, two hundred twenty-two billion, one hundred eleven million, two hundred twelve thousand, one".