21212112110220 has 96 divisors (see below), whose sum is σ = 67397349196800. Its totient is φ = 5536210813632.

The previous prime is 21212112110201. The next prime is 21212112110269. The reversal of 21212112110220 is 2201121121212.

21212112110220 is a `hidden beast` number, since 2 + 1 + 21 + 211 + 211 + 0 + 220 = 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 = 21212112110193 and 21212112110202.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 417864930 + ... + 417915689.

It is an arithmetic number, because the mean of its divisors is an integer number (702055720800).

Almost surely, 2^{21212112110220} is an apocalyptic number.

21212112110220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212112110220 is an abundant number, since it is smaller than the sum of its proper divisors (46185237086580).

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

21212112110220 is a wasteful number, since it uses less digits than its factorization.

21212112110220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 835780684 (or 835780676 counting only the distinct ones).

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

Adding to 21212112110220 its reverse (2201121121212), we get a palindrome (23413233231432).

The spelling of 21212112110220 in words is "twenty-one trillion, two hundred twelve billion, one hundred twelve million, one hundred ten thousand, two hundred twenty".