21222001212120 has 96 divisors (see below), whose sum is σ = 69038273304000. Its totient is φ = 5653721811456.

The previous prime is 21222001212073. The next prime is 21222001212149. The reversal of 21222001212120 is 2121210022212.

It is a happy number.

21222001212120 is a `hidden beast` number, since 212 + 220 + 0 + 1 + 21 + 212 + 0 = 666.

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 = 21222001212093 and 21222001212102.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28161520 + ... + 28905279.

It is an arithmetic number, because the mean of its divisors is an integer number (719148680250).

Almost surely, 2^{21222001212120} is an apocalyptic number.

21222001212120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21222001212120 is an abundant number, since it is smaller than the sum of its proper divisors (47816272091880).

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

21222001212120 is a wasteful number, since it uses less digits than its factorization.

21222001212120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57067849 (or 57067842 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21222001212120 its reverse (2121210022212), we get a palindrome (23343211234332).

The spelling of 21222001212120 in words is "twenty-one trillion, two hundred twenty-two billion, one million, two hundred twelve thousand, one hundred twenty".