21111122012220 has 48 divisors (see below), whose sum is σ = 65679046261920. Its totient is φ = 5629632536448.

The previous prime is 21111122012213. The next prime is 21111122012243. The reversal of 21111122012220 is 2221022111112.

21111122012220 is a `hidden beast` number, since 211 + 1 + 1 + 1 + 220 + 12 + 220 = 666.

It is a super-3 number, since 3×21111122012220³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21111122012193 and 21111122012202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19547334657 + ... + 19547335736.

It is an arithmetic number, because the mean of its divisors is an integer number (1368313463790).

Almost surely, 2^{21111122012220} is an apocalyptic number.

21111122012220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21111122012220 is an abundant number, since it is smaller than the sum of its proper divisors (44567924249700).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21111122012220 is a wasteful number, since it uses less digits than its factorization.

21111122012220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39094670411 (or 39094670403 counting only the distinct ones).

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

Adding to 21111122012220 its reverse (2221022111112), we get a palindrome (23332144123332).

The spelling of 21111122012220 in words is "twenty-one trillion, one hundred eleven billion, one hundred twenty-two million, twelve thousand, two hundred twenty".