20111221111221 has 48 divisors (see below), whose sum is σ = 29296268385280. Its totient is φ = 13293995944320.

The previous prime is 20111221111211. The next prime is 20111221111237. The reversal of 20111221111221 is 12211112211102.

It is a happy number.

20111221111221 is a `hidden beast` number, since 2 + 0 + 111 + 221 + 111 + 221 = 666.

It is not a de Polignac number, because 20111221111221 - 2⁹ = 20111221110709 is a prime.

It is a super-2 number, since 2×20111221111221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20111221111194 and 20111221111203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20111221111211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1536021951 + ... + 1536035043.

Almost surely, 2^{20111221111221} is an apocalyptic number.

It is an amenable number.

20111221111221 is a deficient number, since it is larger than the sum of its proper divisors (9185047274059).

20111221111221 is a wasteful number, since it uses less digits than its factorization.

20111221111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15466 (or 15463 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 20111221111221 its reverse (12211112211102), we get a palindrome (32322333322323).

The spelling of 20111221111221 in words is "twenty trillion, one hundred eleven billion, two hundred twenty-one million, one hundred eleven thousand, two hundred twenty-one".