21212222111001 has 28 divisors (see below), whose sum is σ = 31811547711600. Its totient is φ = 14138029432440.

The previous prime is 21212222110987. The next prime is 21212222111039. The reversal of 21212222111001 is 10011122221212.

21212222111001 is a `hidden beast` number, since 212 + 122 + 221 + 110 + 0 + 1 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-21212222111001 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21212222118001) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 561195 + ... + 6537536.

Almost surely, 2^{21212222111001} is an apocalyptic number.

It is an amenable number.

21212222111001 is a deficient number, since it is larger than the sum of its proper divisors (10599325600599).

21212222111001 is an frugal number, since it uses more digits than its factorization.

21212222111001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7102848 (or 7102833 counting only the distinct ones).

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

Adding to 21212222111001 its reverse (10011122221212), we get a palindrome (31223344332213).

The spelling of 21212222111001 in words is "twenty-one trillion, two hundred twelve billion, two hundred twenty-two million, one hundred eleven thousand, one".