21121021112220 has 36 divisors (see below), whose sum is σ = 64067097374280. Its totient is φ = 5632272296544.

The previous prime is 21121021112207. The next prime is 21121021112231. The reversal of 21121021112220 is 2221112012112.

21121021112220 is a `hidden beast` number, since 2 + 11 + 210 + 211 + 12 + 220 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

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 = 21121021112193 and 21121021112202.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 58669502910 + ... + 58669503269.

It is an arithmetic number, because the mean of its divisors is an integer number (1779641593730).

Almost surely, 2^{21121021112220} is an apocalyptic number.

21121021112220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121021112220 is an abundant number, since it is smaller than the sum of its proper divisors (42946076262060).

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

21121021112220 is a wasteful number, since it uses less digits than its factorization.

21121021112220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117339006194 (or 117339006189 counting only the distinct ones).

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

Adding to 21121021112220 its reverse (2221112012112), we get a palindrome (23342133124332).

The spelling of 21121021112220 in words is "twenty-one trillion, one hundred twenty-one billion, twenty-one million, one hundred twelve thousand, two hundred twenty".